Merge "Update preconditions to be asserts..." into nyc-dev

29 files changed, 129 insertions, 145 deletions

diff --git a/packages/DocumentsUI/Android.mk b/packages/DocumentsUI/Android.mk
index e1650e1bb411..6dfc3bbe8921 100644
--- a/packages/DocumentsUI/Android.mk
+++ b/packages/DocumentsUI/Android.mk
@@ -30,6 +30,10 @@ LOCAL_AAPT_FLAGS := \
   --extra-packages android.support.design \
   --extra-packages android.support.v7.recyclerview
 
+LOCAL_JACK_FLAGS := \
+  -D jack.assert.policy=enable \
+  -D jack.optimization.inner-class.accessors=true
+
 LOCAL_PACKAGE_NAME := DocumentsUI
 LOCAL_CERTIFICATE := platform
 
diff --git a/packages/DocumentsUI/src/com/android/documentsui/BaseActivity.java b/packages/DocumentsUI/src/com/android/documentsui/BaseActivity.java
index 95c49ffe8a92..46cbbdf81c4e 100644
--- a/packages/DocumentsUI/src/com/android/documentsui/BaseActivity.java
+++ b/packages/DocumentsUI/src/com/android/documentsui/BaseActivity.java
@@ -22,8 +22,6 @@ import static com.android.documentsui.dirlist.DirectoryFragment.ANIM_ENTER;
 import static com.android.documentsui.dirlist.DirectoryFragment.ANIM_LEAVE;
 import static com.android.documentsui.dirlist.DirectoryFragment.ANIM_NONE;
 import static com.android.documentsui.dirlist.DirectoryFragment.ANIM_SIDE;
-import static com.android.internal.util.Preconditions.checkArgument;
-import static com.google.common.base.Preconditions.checkState;
 
 import android.app.Activity;
 import android.app.Fragment;
@@ -54,7 +52,6 @@ import com.android.documentsui.dirlist.Model;
 import com.android.documentsui.model.DocumentInfo;
 import com.android.documentsui.model.DocumentStack;
 import com.android.documentsui.model.RootInfo;
-import com.android.internal.util.Preconditions;
 
 import java.io.FileNotFoundException;
 import java.util.ArrayList;
@@ -330,7 +327,8 @@ public abstract class BaseActivity extends Activity
     }
 
     void openContainerDocument(DocumentInfo doc) {
-        checkArgument(doc.isContainer());
+        assert(doc.isContainer());
+
         mState.pushDocument(doc);
         // Show an opening animation only if pressing "back" would get us back to the
         // previous directory. Especially after opening a root document, pressing
@@ -373,7 +371,8 @@ public abstract class BaseActivity extends Activity
     @Override
     public void onSearchChanged(@Nullable String query) {
         // We should not get here if root is not searchable
-        checkState(canSearchRoot());
+        assert(canSearchRoot());
+
         reloadSearch(query);
     }
 
@@ -673,7 +672,8 @@ public abstract class BaseActivity extends Activity
 
         @Override
         protected RootInfo run(RootInfo... roots) {
-            checkArgument(roots.length == 1);
+            assert(roots.length == 1);
+
             final RootInfo currentRoot = roots[0];
             final Collection<RootInfo> cachedRoots = mOwner.mRoots.getRootsBlocking();
             RootInfo homeRoot = null;
@@ -686,7 +686,7 @@ public abstract class BaseActivity extends Activity
                     return null;
                 }
             }
-            Preconditions.checkNotNull(homeRoot);
+            assert(homeRoot != null);
             mHome = mOwner.getRootDocumentBlocking(homeRoot);
             return homeRoot;
         }
diff --git a/packages/DocumentsUI/src/com/android/documentsui/DocumentClipper.java b/packages/DocumentsUI/src/com/android/documentsui/DocumentClipper.java
index b3c28469e71d..15bfc3b93087 100644
--- a/packages/DocumentsUI/src/com/android/documentsui/DocumentClipper.java
+++ b/packages/DocumentsUI/src/com/android/documentsui/DocumentClipper.java
@@ -28,7 +28,6 @@ import android.support.annotation.Nullable;
 import android.util.Log;
 
 import com.android.documentsui.model.DocumentInfo;
-import com.android.internal.util.Preconditions;
 
 import libcore.io.IoUtils;
 
@@ -85,7 +84,7 @@ public final class DocumentClipper {
      * This should be run from inside an AsyncTask.
      */
     public List<DocumentInfo> getDocumentsFromClipData(ClipData clipData) {
-        Preconditions.checkNotNull(clipData);
+        assert(clipData != null);
         final List<DocumentInfo> srcDocs = new ArrayList<>();
 
         int count = clipData.getItemCount();
diff --git a/packages/DocumentsUI/src/com/android/documentsui/DocumentsActivity.java b/packages/DocumentsUI/src/com/android/documentsui/DocumentsActivity.java
index ed531a8e1be3..12a41862e436 100644
--- a/packages/DocumentsUI/src/com/android/documentsui/DocumentsActivity.java
+++ b/packages/DocumentsUI/src/com/android/documentsui/DocumentsActivity.java
@@ -23,7 +23,6 @@ import static com.android.documentsui.State.ACTION_OPEN;
 import static com.android.documentsui.State.ACTION_OPEN_TREE;
 import static com.android.documentsui.State.ACTION_PICK_COPY_DESTINATION;
 import static com.android.documentsui.dirlist.DirectoryFragment.ANIM_NONE;
-import static com.android.internal.util.Preconditions.checkArgument;
 
 import android.app.Activity;
 import android.app.Fragment;
@@ -333,7 +332,7 @@ public class DocumentsActivity extends BaseActivity {
 
     @Override
     void onDirectoryCreated(DocumentInfo doc) {
-        checkArgument(doc.isDirectory());
+        assert(doc.isDirectory());
         openContainerDocument(doc);
     }
 
diff --git a/packages/DocumentsUI/src/com/android/documentsui/DownloadsActivity.java b/packages/DocumentsUI/src/com/android/documentsui/DownloadsActivity.java
index 536feeb4ecc8..b5d3ea082d50 100644
--- a/packages/DocumentsUI/src/com/android/documentsui/DownloadsActivity.java
+++ b/packages/DocumentsUI/src/com/android/documentsui/DownloadsActivity.java
@@ -16,10 +16,8 @@
 
 package com.android.documentsui;
 
-import static com.android.documentsui.Shared.DEBUG;
 import static com.android.documentsui.State.ACTION_MANAGE;
 import static com.android.documentsui.dirlist.DirectoryFragment.ANIM_NONE;
-import static com.android.internal.util.Preconditions.checkState;
 
 import android.app.Activity;
 import android.app.Fragment;
@@ -41,7 +39,6 @@ import com.android.documentsui.dirlist.DirectoryFragment;
 import com.android.documentsui.dirlist.Model;
 import com.android.documentsui.model.DocumentInfo;
 import com.android.documentsui.model.RootInfo;
-import com.android.internal.util.Preconditions;
 
 import java.util.Arrays;
 import java.util.List;
@@ -121,11 +118,11 @@ public class DownloadsActivity extends BaseActivity {
         final RootInfo root = getCurrentRoot();
         final DocumentInfo cwd = getCurrentDirectory();
 
-        if (DEBUG) checkState(!mSearchManager.isSearching());
+        assert(!mSearchManager.isSearching());
 
         // If started in manage roots mode, there has to be a cwd (i.e. the root dir of the managed
         // root).
-        Preconditions.checkNotNull(cwd);
+        assert(cwd != null);
 
         // Normal boring directory
         DirectoryFragment.showDirectory(fm, root, cwd, anim);
@@ -133,7 +130,8 @@ public class DownloadsActivity extends BaseActivity {
 
     @Override
     public void onDocumentPicked(DocumentInfo doc, Model model) {
-        Preconditions.checkArgument(!doc.isDirectory());
+        assert(!doc.isDirectory());
+
         // First try managing the document; we expect manager to filter
         // based on authority, so we don't grant.
         final Intent manage = new Intent(DocumentsContract.ACTION_MANAGE_DOCUMENT);
diff --git a/packages/DocumentsUI/src/com/android/documentsui/DrawerController.java b/packages/DocumentsUI/src/com/android/documentsui/DrawerController.java
index bcf69c44070a..9fceff569d76 100644
--- a/packages/DocumentsUI/src/com/android/documentsui/DrawerController.java
+++ b/packages/DocumentsUI/src/com/android/documentsui/DrawerController.java
@@ -16,8 +16,6 @@
 
 package com.android.documentsui;
 
-import static com.android.internal.util.Preconditions.checkArgument;
-
 import android.app.Activity;
 import android.support.v4.app.ActionBarDrawerToggle;
 import android.support.v4.widget.DrawerLayout;
@@ -83,7 +81,7 @@ abstract class DrawerController implements DrawerListener {
                 DrawerLayout layout, View drawer, ActionBarDrawerToggle toggle,
                 Toolbar drawerToolbar) {
             mToolbar = drawerToolbar;
-            checkArgument(layout != null);
+            assert(layout != null);
 
             mLayout = layout;
             mDrawer = drawer;
diff --git a/packages/DocumentsUI/src/com/android/documentsui/FilesActivity.java b/packages/DocumentsUI/src/com/android/documentsui/FilesActivity.java
index a3378ad7e3bd..c17be067d55d 100644
--- a/packages/DocumentsUI/src/com/android/documentsui/FilesActivity.java
+++ b/packages/DocumentsUI/src/com/android/documentsui/FilesActivity.java
@@ -19,8 +19,6 @@ package com.android.documentsui;
 import static com.android.documentsui.OperationDialogFragment.DIALOG_TYPE_UNKNOWN;
 import static com.android.documentsui.Shared.DEBUG;
 import static com.android.documentsui.dirlist.DirectoryFragment.ANIM_NONE;
-import static com.android.internal.util.Preconditions.checkArgument;
-import static com.android.internal.util.Preconditions.checkState;
 
 import android.app.Activity;
 import android.app.FragmentManager;
@@ -97,11 +95,11 @@ public class FilesActivity extends BaseActivity {
             // Launch URIs support sensible activity management, but don't specify a real
             // content target.
             if (DEBUG) Log.d(TAG, "Launching with non-empty stack.");
-            checkState(uri == null || uri.getAuthority() == null ||
+            assert(uri == null || uri.getAuthority() == null ||
                     LauncherActivity.isLaunchUri(uri));
             refreshCurrentRootAndDirectory(ANIM_NONE);
         } else if (intent.getAction() == Intent.ACTION_VIEW) {
-            checkArgument(uri != null);
+            assert(uri != null);
             new OpenUriForViewTask(this).executeOnExecutor(
                     ProviderExecutor.forAuthority(uri.getAuthority()), uri);
         } else if (DocumentsContract.isRootUri(this, uri)) {
@@ -143,7 +141,7 @@ public class FilesActivity extends BaseActivity {
         state.allowMultiple = true;
 
         // Options specific to the DocumentsActivity.
-        checkArgument(!intent.hasExtra(Intent.EXTRA_LOCAL_ONLY));
+        assert(!intent.hasExtra(Intent.EXTRA_LOCAL_ONLY));
 
         final DocumentStack stack = intent.getParcelableExtra(Shared.EXTRA_STACK);
         if (stack != null) {
@@ -212,7 +210,7 @@ public class FilesActivity extends BaseActivity {
     public boolean onOptionsItemSelected(MenuItem item) {
         switch (item.getItemId()) {
             case R.id.menu_create_dir:
-                checkState(canCreateDirectory());
+                assert(canCreateDirectory());
                 showCreateDirectoryDialog();
                 return true;
             case R.id.menu_new_window:
@@ -250,7 +248,7 @@ public class FilesActivity extends BaseActivity {
         final RootInfo root = getCurrentRoot();
         final DocumentInfo cwd = getCurrentDirectory();
 
-        if (DEBUG) checkState(!mSearchManager.isSearching());
+        assert(!mSearchManager.isSearching());
 
         if (cwd == null) {
             DirectoryFragment.showRecentsOpen(fm, anim);
diff --git a/packages/DocumentsUI/src/com/android/documentsui/LocalPreferences.java b/packages/DocumentsUI/src/com/android/documentsui/LocalPreferences.java
index 4bffc49e5ac0..170fb891f97d 100644
--- a/packages/DocumentsUI/src/com/android/documentsui/LocalPreferences.java
+++ b/packages/DocumentsUI/src/com/android/documentsui/LocalPreferences.java
@@ -17,7 +17,6 @@
 package com.android.documentsui;
 
 import static com.android.documentsui.State.MODE_UNKNOWN;
-import static com.android.internal.util.Preconditions.checkArgument;
 
 import android.content.Context;
 import android.preference.PreferenceManager;
@@ -59,7 +58,8 @@ public class LocalPreferences {
     }
 
     public static void setViewMode(Context context, RootInfo root, @ViewMode int viewMode) {
-        checkArgument(viewMode != MODE_UNKNOWN);
+        assert(viewMode != MODE_UNKNOWN);
+
         PreferenceManager.getDefaultSharedPreferences(context).edit()
                 .putInt(createKey(root), viewMode).apply();
     }
diff --git a/packages/DocumentsUI/src/com/android/documentsui/Metrics.java b/packages/DocumentsUI/src/com/android/documentsui/Metrics.java
index 699605f5cdcb..bff65d5b5caf 100644
--- a/packages/DocumentsUI/src/com/android/documentsui/Metrics.java
+++ b/packages/DocumentsUI/src/com/android/documentsui/Metrics.java
@@ -17,7 +17,6 @@
 package com.android.documentsui;
 
 import static com.android.documentsui.Shared.DEBUG;
-import static com.android.internal.util.Preconditions.checkArgument;
 
 import android.annotation.IntDef;
 import android.annotation.Nullable;
@@ -363,7 +362,7 @@ public final class Metrics {
         if (operationType == FileOperationService.OPERATION_DELETE) {
             logHistogram(context, histogram, FILEOP_DELETE);
         } else {
-            checkArgument(dst != null);
+            assert(dst != null);
             @Provider int providerType =
                     isSystemProvider(dst.authority) ? PROVIDER_SYSTEM : PROVIDER_EXTERNAL;
             logHistogram(context, histogram, getOpCode(operationType, providerType));
diff --git a/packages/DocumentsUI/src/com/android/documentsui/PickFragment.java b/packages/DocumentsUI/src/com/android/documentsui/PickFragment.java
index 32543c82621e..933506c258f2 100644
--- a/packages/DocumentsUI/src/com/android/documentsui/PickFragment.java
+++ b/packages/DocumentsUI/src/com/android/documentsui/PickFragment.java
@@ -19,7 +19,6 @@ package com.android.documentsui;
 import static com.android.documentsui.services.FileOperationService.OPERATION_DELETE;
 import static com.android.documentsui.services.FileOperationService.OPERATION_MOVE;
 import static com.android.documentsui.services.FileOperationService.OPERATION_UNKNOWN;
-import static com.android.internal.util.Preconditions.checkArgument;
 
 import android.app.Activity;
 import android.app.Fragment;
@@ -101,7 +100,8 @@ public class PickFragment extends Fragment {
      */
     public void setPickTarget(
             int action, @OpType int copyOperationSubType, DocumentInfo pickTarget) {
-        checkArgument(copyOperationSubType != OPERATION_DELETE);
+        assert(copyOperationSubType != OPERATION_DELETE);
+
         mAction = action;
         mCopyOperationSubType = copyOperationSubType;
         mPickTarget = pickTarget;
diff --git a/packages/DocumentsUI/src/com/android/documentsui/ProviderExecutor.java b/packages/DocumentsUI/src/com/android/documentsui/ProviderExecutor.java
index b0e332faa3fc..8145edc4d7db 100644
--- a/packages/DocumentsUI/src/com/android/documentsui/ProviderExecutor.java
+++ b/packages/DocumentsUI/src/com/android/documentsui/ProviderExecutor.java
@@ -19,7 +19,6 @@ package com.android.documentsui;
 import android.os.AsyncTask;
 
 import com.android.internal.annotations.GuardedBy;
-import com.android.internal.util.Preconditions;
 
 import java.lang.ref.WeakReference;
 import java.util.ArrayList;
@@ -85,7 +84,7 @@ public class ProviderExecutor extends Thread implements Executor {
     private Executor mNonPreemptingExecutor = new Executor() {
         @Override
         public void execute(Runnable command) {
-            Preconditions.checkNotNull(command);
+            assert(command != null);
             mQueue.add(command);
         }
     };
@@ -93,7 +92,7 @@ public class ProviderExecutor extends Thread implements Executor {
     @Override
     public void execute(Runnable command) {
         preempt();
-        Preconditions.checkNotNull(command);
+        assert(command != null);
         mQueue.add(command);
     }
 
diff --git a/packages/DocumentsUI/src/com/android/documentsui/RootsCache.java b/packages/DocumentsUI/src/com/android/documentsui/RootsCache.java
index c4c5124390e8..ab67a51265e9 100644
--- a/packages/DocumentsUI/src/com/android/documentsui/RootsCache.java
+++ b/packages/DocumentsUI/src/com/android/documentsui/RootsCache.java
@@ -18,7 +18,6 @@ package com.android.documentsui;
 
 import static com.android.documentsui.Shared.DEBUG;
 import static com.android.documentsui.Shared.TAG;
-import static com.android.internal.util.Preconditions.checkState;
 
 import android.content.ContentProviderClient;
 import android.content.ContentResolver;
@@ -41,7 +40,6 @@ import android.util.Log;
 
 import com.android.documentsui.model.RootInfo;
 import com.android.internal.annotations.GuardedBy;
-import com.android.internal.util.Preconditions;
 
 import com.google.common.collect.ArrayListMultimap;
 import com.google.common.collect.Multimap;
@@ -118,17 +116,16 @@ public class RootsCache {
      */
     public void updateAsync() {
         // Verifying an assumption about the recents root being immutable.
-        if (DEBUG) {
-            checkState(mRecentsRoot.authority == null);
-            checkState(mRecentsRoot.rootId == null);
-            checkState(mRecentsRoot.derivedIcon == R.drawable.ic_root_recent);
-            checkState(mRecentsRoot.derivedType == RootInfo.TYPE_RECENTS);
-            checkState(mRecentsRoot.flags == (Root.FLAG_LOCAL_ONLY
-                    | Root.FLAG_SUPPORTS_IS_CHILD
-                    | Root.FLAG_SUPPORTS_CREATE));
-            checkState(mRecentsRoot.title == mContext.getString(R.string.root_recent));
-            checkState(mRecentsRoot.availableBytes == -1);
-        }
+        assert(mRecentsRoot.authority == null);
+        assert(mRecentsRoot.rootId == null);
+        assert(mRecentsRoot.derivedIcon == R.drawable.ic_root_recent);
+        assert(mRecentsRoot.derivedType == RootInfo.TYPE_RECENTS);
+        assert(mRecentsRoot.flags == (Root.FLAG_LOCAL_ONLY
+                | Root.FLAG_SUPPORTS_IS_CHILD
+                | Root.FLAG_SUPPORTS_CREATE));
+        assert(mRecentsRoot.title == mContext.getString(R.string.root_recent));
+        assert(mRecentsRoot.availableBytes == -1);
+
         new UpdateTask().executeOnExecutor(AsyncTask.THREAD_POOL_EXECUTOR);
     }
 
diff --git a/packages/DocumentsUI/src/com/android/documentsui/SearchViewManager.java b/packages/DocumentsUI/src/com/android/documentsui/SearchViewManager.java
index 8beb245934d1..63dc2ee3796e 100644
--- a/packages/DocumentsUI/src/com/android/documentsui/SearchViewManager.java
+++ b/packages/DocumentsUI/src/com/android/documentsui/SearchViewManager.java
@@ -61,7 +61,8 @@ final class SearchViewManager implements
     }
 
     public void install(DocumentsToolbar actionBar) {
-        assert (mActionBar == null);
+        // assert(mActionBar == null);
+
         mActionBar = actionBar;
         mMenu = actionBar.getSearchMenu();
         mView = (SearchView) mMenu.getActionView();
diff --git a/packages/DocumentsUI/src/com/android/documentsui/Shared.java b/packages/DocumentsUI/src/com/android/documentsui/Shared.java
index a288fe8f30ab..99c2d80bdfd9 100644
--- a/packages/DocumentsUI/src/com/android/documentsui/Shared.java
+++ b/packages/DocumentsUI/src/com/android/documentsui/Shared.java
@@ -28,6 +28,10 @@ import java.util.List;
 /** @hide */
 public final class Shared {
 
+    public static final String TAG = "Documents";
+
+    public static final boolean DEBUG = true;
+
     /** Intent action name to pick a copy destination. */
     public static final String ACTION_PICK_COPY_DESTINATION =
             "com.android.documentsui.PICK_COPY_DESTINATION";
@@ -79,9 +83,6 @@ public final class Shared {
      */
     public static final String EXTRA_IGNORE_STATE = "ignoreState";
 
-    public static final boolean DEBUG = true;
-    public static final String TAG = "Documents";
-
 
     /**
      * String prefix used to indicate the document is a directory.
diff --git a/packages/DocumentsUI/src/com/android/documentsui/Snackbars.java b/packages/DocumentsUI/src/com/android/documentsui/Snackbars.java
index 48c1a733703c..b4d79715d479 100644
--- a/packages/DocumentsUI/src/com/android/documentsui/Snackbars.java
+++ b/packages/DocumentsUI/src/com/android/documentsui/Snackbars.java
@@ -16,8 +16,6 @@
 
 package com.android.documentsui;
 
-import static com.android.internal.util.Preconditions.checkNotNull;
-
 import android.app.Activity;
 import android.support.design.widget.Snackbar;
 import android.view.View;
@@ -26,12 +24,13 @@ public final class Snackbars {
     private Snackbars() {}
 
     public static final Snackbar makeSnackbar(Activity activity, int messageId, int duration) {
-        return Snackbars.makeSnackbar(activity, activity.getResources().getText(messageId), duration);
+        return Snackbars.makeSnackbar(
+                activity, activity.getResources().getText(messageId), duration);
     }
 
-    public static final Snackbar makeSnackbar(Activity activity, CharSequence message, int duration)
-    {
-        final View view = checkNotNull(activity.findViewById(R.id.coordinator_layout));
+    public static final Snackbar makeSnackbar(
+            Activity activity, CharSequence message, int duration) {
+        final View view = activity.findViewById(R.id.coordinator_layout);
         return Snackbar.make(view, message, duration);
     }
 }
diff --git a/packages/DocumentsUI/src/com/android/documentsui/dirlist/DirectoryFragment.java b/packages/DocumentsUI/src/com/android/documentsui/dirlist/DirectoryFragment.java
index d1b22643d006..dfceff8d22b0 100644
--- a/packages/DocumentsUI/src/com/android/documentsui/dirlist/DirectoryFragment.java
+++ b/packages/DocumentsUI/src/com/android/documentsui/dirlist/DirectoryFragment.java
@@ -23,9 +23,6 @@ import static com.android.documentsui.State.MODE_LIST;
 import static com.android.documentsui.State.SORT_ORDER_UNKNOWN;
 import static com.android.documentsui.model.DocumentInfo.getCursorInt;
 import static com.android.documentsui.model.DocumentInfo.getCursorString;
-import static com.android.internal.util.Preconditions.checkNotNull;
-import static com.android.internal.util.Preconditions.checkState;
-import static com.google.common.base.Preconditions.checkArgument;
 
 import android.annotation.IntDef;
 import android.annotation.StringRes;
@@ -102,6 +99,7 @@ import com.android.documentsui.model.RootInfo;
 import com.android.documentsui.services.FileOperationService;
 import com.android.documentsui.services.FileOperationService.OpType;
 import com.android.documentsui.services.FileOperations;
+
 import com.google.common.collect.Lists;
 
 import java.lang.annotation.Retention;
@@ -359,7 +357,9 @@ public class DirectoryFragment extends Fragment
 
     private boolean handleViewItem(String id) {
         final Cursor cursor = mModel.getItem(id);
-        checkNotNull(cursor, "Cursor cannot be null.");
+
+        assert(cursor != null);
+
         final String docMimeType = getCursorString(cursor, Document.COLUMN_MIME_TYPE);
         final int docFlags = getCursorInt(cursor, Document.COLUMN_FLAGS);
         if (mTuner.isDocumentEnabled(docMimeType, docFlags)) {
@@ -430,7 +430,8 @@ public class DirectoryFragment extends Fragment
         int cellMargin = 2 * getResources().getDimensionPixelSize(R.dimen.grid_item_margin);
         int viewPadding = mRecView.getPaddingLeft() + mRecView.getPaddingRight();
 
-        checkState(mRecView.getWidth() > 0);
+        assert(mRecView.getWidth() > 0);
+
         int columnCount = Math.max(1,
                 (mRecView.getWidth() - viewPadding) / (cellWidth + cellMargin));
 
@@ -471,7 +472,9 @@ public class DirectoryFragment extends Fragment
         public boolean onBeforeItemStateChange(String modelId, boolean selected) {
             if (selected) {
                 final Cursor cursor = mModel.getItem(modelId);
-                checkNotNull(cursor, "Cursor cannot be null.");
+
+                assert(cursor != null);
+
                 final String docMimeType = getCursorString(cursor, Document.COLUMN_MIME_TYPE);
                 final int docFlags = getCursorInt(cursor, Document.COLUMN_FLAGS);
                 return mTuner.canSelectType(docMimeType, docFlags);
@@ -564,7 +567,7 @@ public class DirectoryFragment extends Fragment
         }
 
         private void updateActionMenu() {
-            checkNotNull(mMenu);
+            assert(mMenu != null);
 
             // Delegate update logic to our owning action, since specialized logic is desired.
             mTuner.updateActionMenu(mMenu, mType, canDeleteSelection(), canRenameSelection());
@@ -699,8 +702,8 @@ public class DirectoryFragment extends Fragment
     }
 
     private void deleteDocuments(final Selection selected) {
+        assert(!selected.isEmpty());
 
-        checkArgument(!selected.isEmpty());
         final DocumentInfo srcParent = getDisplayState().stack.peek();
         new GetDocumentsTask() {
             @Override
@@ -777,7 +780,7 @@ public class DirectoryFragment extends Fragment
     private void renameDocuments(Selection selected) {
         // Batch renaming not supported
         // Rename option is only available in menu when 1 document selected
-        checkArgument(selected.size() == 1);
+        assert(selected.size() == 1);
 
         new GetDocumentsTask() {
             @Override
@@ -890,7 +893,8 @@ public class DirectoryFragment extends Fragment
     }
 
     private void copyFromClipData(final ClipData clipData, final DocumentInfo destination) {
-        checkNotNull(clipData);
+        assert(clipData != null);
+
         new AsyncTask<Void, Void, List<DocumentInfo>>() {
 
             @Override
@@ -941,7 +945,7 @@ public class DirectoryFragment extends Fragment
     }
 
     void copySelectionToClipboard(Selection selection) {
-        checkArgument(!selection.isEmpty());
+        assert(!selection.isEmpty());
         new GetDocumentsTask() {
             @Override
             void onDocumentsReady(List<DocumentInfo> docs) {
@@ -1059,7 +1063,7 @@ public class DirectoryFragment extends Fragment
             String id = getModelId(v);
             if (id != null) {
                 Cursor dstCursor = mModel.getItem(id);
-                checkNotNull(dstCursor, "Cursor cannot be null.");
+                assert(dstCursor != null);
                 return DocumentInfo.fromDirectoryCursor(dstCursor);
             }
 
@@ -1132,10 +1136,11 @@ public class DirectoryFragment extends Fragment
         }
 
         final Cursor cursor = mModel.getItem(modelId);
-        checkNotNull(cursor, "Cursor cannot be null.");
-        final DocumentInfo doc = DocumentInfo.fromDirectoryCursor(cursor);
 
-        return Lists.newArrayList(doc);
+        assert(cursor != null);
+
+        return Lists.newArrayList(
+                DocumentInfo.fromDirectoryCursor(cursor));
     }
 
     private Drawable getDragShadowIcon(List<DocumentInfo> docs) {
diff --git a/packages/DocumentsUI/src/com/android/documentsui/dirlist/DocumentHolder.java b/packages/DocumentsUI/src/com/android/documentsui/dirlist/DocumentHolder.java
index 2967a908678d..3b5ce87ebfb0 100644
--- a/packages/DocumentsUI/src/com/android/documentsui/dirlist/DocumentHolder.java
+++ b/packages/DocumentsUI/src/com/android/documentsui/dirlist/DocumentHolder.java
@@ -16,9 +16,6 @@
 
 package com.android.documentsui.dirlist;
 
-import static com.android.internal.util.Preconditions.checkNotNull;
-import static com.android.internal.util.Preconditions.checkState;
-
 import android.content.Context;
 import android.database.Cursor;
 import android.graphics.Rect;
@@ -97,19 +94,20 @@ public abstract class DocumentHolder
     @Override
     public boolean onKey(View v, int keyCode, KeyEvent event) {
         // Event listener should always be set.
-        checkNotNull(mEventListener);
+        assert(mEventListener != null);
+
         return mEventListener.onKey(this,  keyCode,  event);
     }
 
     public void addEventListener(DocumentHolder.EventListener listener) {
         // Just handle one for now; switch to a list if necessary.
-        checkState(mEventListener == null);
+        assert(mEventListener == null);
         mEventListener = listener;
     }
 
     public void addOnKeyListener(View.OnKeyListener listener) {
         // Just handle one for now; switch to a list if necessary.
-        checkState(mKeyListener == null);
+        assert(mKeyListener == null);
         mKeyListener = listener;
     }
 
diff --git a/packages/DocumentsUI/src/com/android/documentsui/dirlist/FragmentTuner.java b/packages/DocumentsUI/src/com/android/documentsui/dirlist/FragmentTuner.java
index 8ef891033901..f99ec85c358b 100644
--- a/packages/DocumentsUI/src/com/android/documentsui/dirlist/FragmentTuner.java
+++ b/packages/DocumentsUI/src/com/android/documentsui/dirlist/FragmentTuner.java
@@ -22,7 +22,6 @@ import static com.android.documentsui.State.ACTION_GET_CONTENT;
 import static com.android.documentsui.State.ACTION_MANAGE;
 import static com.android.documentsui.State.ACTION_OPEN;
 import static com.android.documentsui.State.ACTION_OPEN_TREE;
-import static com.android.internal.util.Preconditions.checkArgument;
 
 import android.content.Context;
 import android.provider.DocumentsContract.Document;
@@ -172,7 +171,7 @@ public abstract class FragmentTuner {
         @Override
         public void updateActionMenu(
                 Menu menu, @ResultType int resultType, boolean canDelete, boolean canRename) {
-            checkArgument(resultType != DirectoryFragment.TYPE_RECENT_OPEN);
+            assert(resultType != DirectoryFragment.TYPE_RECENT_OPEN);
 
             MenuItem open = menu.findItem(R.id.menu_open);
             MenuItem delete = menu.findItem(R.id.menu_delete);
diff --git a/packages/DocumentsUI/src/com/android/documentsui/dirlist/GridDirectoryHolder.java b/packages/DocumentsUI/src/com/android/documentsui/dirlist/GridDirectoryHolder.java
index a0ff1b5812ae..90b23419fcd3 100644
--- a/packages/DocumentsUI/src/com/android/documentsui/dirlist/GridDirectoryHolder.java
+++ b/packages/DocumentsUI/src/com/android/documentsui/dirlist/GridDirectoryHolder.java
@@ -17,7 +17,6 @@
 package com.android.documentsui.dirlist;
 
 import static com.android.documentsui.model.DocumentInfo.getCursorString;
-import static com.android.internal.util.Preconditions.checkNotNull;
 
 import android.content.Context;
 import android.database.Cursor;
@@ -58,7 +57,7 @@ final class GridDirectoryHolder extends DocumentHolder {
      * @param state Current display state.
      */
     public void bind(Cursor cursor, String modelId, State state) {
-        checkNotNull(cursor, "Cursor cannot be null.");
+        assert(cursor != null);
 
         this.modelId = modelId;
 
diff --git a/packages/DocumentsUI/src/com/android/documentsui/dirlist/GridDocumentHolder.java b/packages/DocumentsUI/src/com/android/documentsui/dirlist/GridDocumentHolder.java
index 8eaed17e8676..a4bce1626fb4 100644
--- a/packages/DocumentsUI/src/com/android/documentsui/dirlist/GridDocumentHolder.java
+++ b/packages/DocumentsUI/src/com/android/documentsui/dirlist/GridDocumentHolder.java
@@ -19,7 +19,6 @@ package com.android.documentsui.dirlist;
 import static com.android.documentsui.model.DocumentInfo.getCursorInt;
 import static com.android.documentsui.model.DocumentInfo.getCursorLong;
 import static com.android.documentsui.model.DocumentInfo.getCursorString;
-import static com.android.internal.util.Preconditions.checkNotNull;
 
 import android.content.Context;
 import android.database.Cursor;
@@ -79,9 +78,9 @@ final class GridDocumentHolder extends DocumentHolder {
      * @param state Current display state.
      */
     public void bind(Cursor cursor, String modelId, State state) {
-        this.modelId = modelId;
+        assert(cursor != null);
 
-        checkNotNull(cursor, "Cursor cannot be null.");
+        this.modelId = modelId;
 
         final String docAuthority = getCursorString(cursor, RootCursorWrapper.COLUMN_AUTHORITY);
         final String docId = getCursorString(cursor, Document.COLUMN_DOCUMENT_ID);
diff --git a/packages/DocumentsUI/src/com/android/documentsui/dirlist/ListDocumentHolder.java b/packages/DocumentsUI/src/com/android/documentsui/dirlist/ListDocumentHolder.java
index be6413bfbf6c..b940ffbcda30 100644
--- a/packages/DocumentsUI/src/com/android/documentsui/dirlist/ListDocumentHolder.java
+++ b/packages/DocumentsUI/src/com/android/documentsui/dirlist/ListDocumentHolder.java
@@ -19,7 +19,6 @@ package com.android.documentsui.dirlist;
 import static com.android.documentsui.model.DocumentInfo.getCursorInt;
 import static com.android.documentsui.model.DocumentInfo.getCursorLong;
 import static com.android.documentsui.model.DocumentInfo.getCursorString;
-import static com.android.internal.util.Preconditions.checkNotNull;
 
 import android.content.Context;
 import android.database.Cursor;
@@ -79,9 +78,9 @@ final class ListDocumentHolder extends DocumentHolder {
      */
     @Override
     public void bind(Cursor cursor, String modelId, State state) {
-        this.modelId = modelId;
+        assert(cursor != null);
 
-        checkNotNull(cursor, "Cursor cannot be null.");
+        this.modelId = modelId;
 
         final String docAuthority = getCursorString(cursor, RootCursorWrapper.COLUMN_AUTHORITY);
         final String docId = getCursorString(cursor, Document.COLUMN_DOCUMENT_ID);
diff --git a/packages/DocumentsUI/src/com/android/documentsui/dirlist/Model.java b/packages/DocumentsUI/src/com/android/documentsui/dirlist/Model.java
index 9684a5a0a2c2..5e55e1a8b9ea 100644
--- a/packages/DocumentsUI/src/com/android/documentsui/dirlist/Model.java
+++ b/packages/DocumentsUI/src/com/android/documentsui/dirlist/Model.java
@@ -22,11 +22,9 @@ import static com.android.documentsui.State.SORT_ORDER_LAST_MODIFIED;
 import static com.android.documentsui.State.SORT_ORDER_SIZE;
 import static com.android.documentsui.model.DocumentInfo.getCursorLong;
 import static com.android.documentsui.model.DocumentInfo.getCursorString;
-import static com.android.internal.util.Preconditions.checkNotNull;
 
 import android.database.Cursor;
 import android.os.Bundle;
-import android.os.Looper;
 import android.provider.DocumentsContract;
 import android.provider.DocumentsContract.Document;
 import android.support.annotation.Nullable;
@@ -381,9 +379,9 @@ public class Model {
         final List<DocumentInfo> docs =  new ArrayList<>(size);
         for (String modelId: items.getAll()) {
             final Cursor cursor = getItem(modelId);
-            checkNotNull(cursor, "Cursor cannot be null.");
-            final DocumentInfo doc = DocumentInfo.fromDirectoryCursor(cursor);
-            docs.add(doc);
+            assert(cursor != null);
+
+            docs.add(DocumentInfo.fromDirectoryCursor(cursor));
         }
         return docs;
     }
diff --git a/packages/DocumentsUI/src/com/android/documentsui/dirlist/MultiSelectManager.java b/packages/DocumentsUI/src/com/android/documentsui/dirlist/MultiSelectManager.java
index 4cf1048b6ab4..b0cc09a134f9 100644
--- a/packages/DocumentsUI/src/com/android/documentsui/dirlist/MultiSelectManager.java
+++ b/packages/DocumentsUI/src/com/android/documentsui/dirlist/MultiSelectManager.java
@@ -19,9 +19,6 @@ package com.android.documentsui.dirlist;
 import static com.android.documentsui.Shared.DEBUG;
 import static com.android.documentsui.dirlist.ModelBackedDocumentsAdapter.ITEM_TYPE_DIRECTORY;
 import static com.android.documentsui.dirlist.ModelBackedDocumentsAdapter.ITEM_TYPE_DOCUMENT;
-import static com.android.internal.util.Preconditions.checkArgument;
-import static com.android.internal.util.Preconditions.checkNotNull;
-import static com.android.internal.util.Preconditions.checkState;
 
 import android.annotation.IntDef;
 import android.graphics.Point;
@@ -134,8 +131,12 @@ public final class MultiSelectManager {
             @SelectionMode int mode,
             @Nullable Selection initialSelection) {
 
-        mEnvironment = checkNotNull(environment, "'environment' cannot be null.");
-        mAdapter = checkNotNull(adapter, "'adapter' cannot be null.");
+        assert(environment != null);
+        assert(adapter != null);
+
+        mEnvironment = environment;
+        mAdapter = adapter;
+
         mSingleSelect = mode == MODE_SINGLE;
         if (initialSelection != null) {
             mSelection.copyFrom(initialSelection);
@@ -168,8 +169,8 @@ public final class MultiSelectManager {
 
                     @Override
                     public void onItemRangeRemoved(int startPosition, int itemCount) {
-                        checkState(startPosition >= 0);
-                        checkState(itemCount > 0);
+                        assert(startPosition >= 0);
+                        assert(itemCount > 0);
 
                         mSelection.cancelProvisionalSelection();
                         // Remove any disappeared IDs from the selection.
@@ -356,7 +357,8 @@ public final class MultiSelectManager {
      * @param modelId
      */
     public void toggleSelection(String modelId) {
-        checkNotNull(modelId);
+        assert(modelId != null);
+
         boolean changed = false;
         if (mSelection.contains(modelId)) {
             changed = attemptDeselect(modelId);
@@ -389,7 +391,8 @@ public final class MultiSelectManager {
      * @param pos The new end position for the selection range.
      */
     void snapRangeSelection(int pos) {
-        checkNotNull(mRanger);
+        assert(mRanger != null);
+
         mRanger.snapSelection(pos);
         notifySelectionChanged();
     }
@@ -436,7 +439,7 @@ public final class MultiSelectManager {
      * @param selected New selection state.
      */
     private void updateRange(int begin, int end, boolean selected) {
-        checkState(end >= begin);
+        assert(end >= begin);
         for (int i = begin; i <= end; i++) {
             String id = mAdapter.getModelId(i);
             if (id == null) {
@@ -474,7 +477,7 @@ public final class MultiSelectManager {
      * @return True if the update was applied.
      */
     private boolean attemptDeselect(String id) {
-        checkArgument(id != null);
+        assert(id != null);
         if (notifyBeforeItemStateChange(id, false)) {
             mSelection.remove(id);
             notifyItemStateChanged(id, false);
@@ -491,7 +494,7 @@ public final class MultiSelectManager {
      * @return True if the update was applied.
      */
     private boolean attemptSelect(String id) {
-        checkArgument(id != null);
+        assert(id != null);
         boolean canSelect = notifyBeforeItemStateChange(id, true);
         if (!canSelect) {
             return false;
@@ -519,7 +522,7 @@ public final class MultiSelectManager {
      * (identified by {@code position}) changes.
      */
     private void notifyItemStateChanged(String id, boolean selected) {
-        checkArgument(id != null);
+        assert(id != null);
         int lastListener = mCallbacks.size() - 1;
         for (int i = lastListener; i > -1; i--) {
             mCallbacks.get(i).onItemStateChanged(id, selected);
@@ -555,8 +558,8 @@ public final class MultiSelectManager {
         }
 
         private void snapSelection(int position) {
-            checkState(mRanger != null);
-            checkArgument(position != RecyclerView.NO_POSITION);
+            assert(mRanger != null);
+            assert(position != RecyclerView.NO_POSITION);
 
             if (mEnd == UNDEFINED || mEnd == mBegin) {
                 // Reset mEnd so it can be established in establishRange.
@@ -568,7 +571,7 @@ public final class MultiSelectManager {
         }
 
         private void establishRange(int position) {
-            checkState(mRanger.mEnd == UNDEFINED);
+            assert(mRanger.mEnd == UNDEFINED);
 
             if (position == mBegin) {
                 mEnd = position;
@@ -584,8 +587,8 @@ public final class MultiSelectManager {
         }
 
         private void reviseRange(int position) {
-            checkState(mEnd != UNDEFINED);
-            checkState(mBegin != mEnd);
+            assert(mEnd != UNDEFINED);
+            assert(mBegin != mEnd);
 
             if (position == mEnd) {
                 if (DEBUG) Log.i(TAG, "Skipping no-op revision click on mEndRange.");
@@ -1185,7 +1188,7 @@ public final class MultiSelectManager {
          * @param input
          */
         private void processInputEvent(InputEvent input) {
-            checkArgument(input.isMouseEvent());
+            assert(input.isMouseEvent());
 
             if (shouldStop(input)) {
                 endBandSelect();
@@ -1199,7 +1202,6 @@ public final class MultiSelectManager {
             }
 
             mCurrentPosition = input.getOrigin();
-            mModel.resizeSelection(input.getOrigin());
             scrollViewIfNecessary();
             resizeBandSelectRectangle();
         }
@@ -1488,6 +1490,7 @@ public final class MultiSelectManager {
          *     top-left of the viewport would have a relative origin of (0, 0), even though its
          *     absolute point has a higher y-value.
          */
+        @VisibleForTesting
         void resizeSelection(Point relativePointer) {
             mPointer = mHelper.createAbsolutePoint(relativePointer);
             updateModel();
@@ -1615,7 +1618,7 @@ public final class MultiSelectManager {
         private void updateSelection(Rect rect) {
             int columnStart =
                     Collections.binarySearch(mColumnBounds, new Limits(rect.left, rect.left));
-            checkState(columnStart >= 0);
+            assert(columnStart >= 0);
             int columnEnd = columnStart;
 
             for (int i = columnStart; i < mColumnBounds.size()
diff --git a/packages/DocumentsUI/src/com/android/documentsui/dirlist/RenameDocumentFragment.java b/packages/DocumentsUI/src/com/android/documentsui/dirlist/RenameDocumentFragment.java
index 38a71ec2d149..0018d01aa85c 100644
--- a/packages/DocumentsUI/src/com/android/documentsui/dirlist/RenameDocumentFragment.java
+++ b/packages/DocumentsUI/src/com/android/documentsui/dirlist/RenameDocumentFragment.java
@@ -17,7 +17,6 @@
 package com.android.documentsui.dirlist;
 
 import static com.android.documentsui.Shared.TAG;
-import static com.android.internal.util.Preconditions.checkArgument;
 
 import android.app.AlertDialog;
 import android.app.Dialog;
@@ -36,9 +35,9 @@ import android.support.annotation.Nullable;
 import android.support.design.widget.Snackbar;
 import android.util.Log;
 import android.view.KeyEvent;
-import android.view.inputmethod.EditorInfo;
 import android.view.LayoutInflater;
 import android.view.View;
+import android.view.inputmethod.EditorInfo;
 import android.widget.EditText;
 import android.widget.TextView;
 import android.widget.TextView.OnEditorActionListener;
@@ -205,7 +204,7 @@ public class RenameDocumentFragment extends DialogFragment {
 
         @Override
         protected DocumentInfo doInBackground(DocumentInfo... document) {
-            checkArgument(document.length == 1);
+            assert(document.length == 1);
             final ContentResolver resolver = mActivity.getContentResolver();
             ContentProviderClient client = null;
 
diff --git a/packages/DocumentsUI/src/com/android/documentsui/dirlist/SectionBreakDocumentsAdapterWrapper.java b/packages/DocumentsUI/src/com/android/documentsui/dirlist/SectionBreakDocumentsAdapterWrapper.java
index 2485ad96a233..3ee5cfc38f8d 100644
--- a/packages/DocumentsUI/src/com/android/documentsui/dirlist/SectionBreakDocumentsAdapterWrapper.java
+++ b/packages/DocumentsUI/src/com/android/documentsui/dirlist/SectionBreakDocumentsAdapterWrapper.java
@@ -16,8 +16,6 @@
 
 package com.android.documentsui.dirlist;
 
-import static com.android.internal.util.Preconditions.checkArgument;
-
 import android.content.Context;
 import android.database.Cursor;
 import android.support.v7.widget.GridLayoutManager;
@@ -204,12 +202,12 @@ final class SectionBreakDocumentsAdapterWrapper extends DocumentsAdapter {
         }
 
         public void onItemRangeChanged(int positionStart, int itemCount, Object payload) {
-            checkArgument(itemCount == 1);
+            assert(itemCount == 1);
             notifyItemRangeChanged(toViewPosition(positionStart), itemCount, payload);
         }
 
         public void onItemRangeInserted(int positionStart, int itemCount) {
-            checkArgument(itemCount == 1);
+            assert(itemCount == 1);
             if (positionStart < mBreakPosition) {
                 mBreakPosition++;
             }
@@ -217,7 +215,7 @@ final class SectionBreakDocumentsAdapterWrapper extends DocumentsAdapter {
         }
 
         public void onItemRangeRemoved(int positionStart, int itemCount) {
-            checkArgument(itemCount == 1);
+            assert(itemCount == 1);
             if (positionStart < mBreakPosition) {
                 mBreakPosition--;
             }
diff --git a/packages/DocumentsUI/src/com/android/documentsui/services/CopyJob.java b/packages/DocumentsUI/src/com/android/documentsui/services/CopyJob.java
index faedd5e2d355..ad48a70c4075 100644
--- a/packages/DocumentsUI/src/com/android/documentsui/services/CopyJob.java
+++ b/packages/DocumentsUI/src/com/android/documentsui/services/CopyJob.java
@@ -29,7 +29,6 @@ import static com.android.documentsui.services.FileOperationService.EXTRA_DIALOG
 import static com.android.documentsui.services.FileOperationService.EXTRA_OPERATION;
 import static com.android.documentsui.services.FileOperationService.EXTRA_SRC_LIST;
 import static com.android.documentsui.services.FileOperationService.OPERATION_COPY;
-import static com.google.common.base.Preconditions.checkArgument;
 
 import android.annotation.StringRes;
 import android.app.Notification;
@@ -95,7 +94,7 @@ class CopyJob extends Job {
             String id, DocumentStack stack, List<DocumentInfo> srcs) {
         super(service, appContext, listener, OPERATION_COPY, id, stack);
 
-        checkArgument(!srcs.isEmpty());
+        assert(!srcs.isEmpty());
         this.mSrcs = srcs;
     }
 
@@ -108,7 +107,7 @@ class CopyJob extends Job {
             @OpType int opType, String id, DocumentStack destination, List<DocumentInfo> srcs) {
         super(service, appContext, listener, opType, id, destination);
 
-        checkArgument(!srcs.isEmpty());
+        assert(!srcs.isEmpty());
         this.mSrcs = srcs;
     }
 
diff --git a/packages/DocumentsUI/src/com/android/documentsui/services/FileOperationService.java b/packages/DocumentsUI/src/com/android/documentsui/services/FileOperationService.java
index 05a3f119c7d6..580fa38258a6 100644
--- a/packages/DocumentsUI/src/com/android/documentsui/services/FileOperationService.java
+++ b/packages/DocumentsUI/src/com/android/documentsui/services/FileOperationService.java
@@ -17,9 +17,6 @@
 package com.android.documentsui.services;
 
 import static com.android.documentsui.Shared.DEBUG;
-import static com.android.internal.util.Preconditions.checkArgument;
-import static com.android.internal.util.Preconditions.checkNotNull;
-import static com.android.internal.util.Preconditions.checkState;
 
 import android.annotation.IntDef;
 import android.app.NotificationManager;
@@ -136,12 +133,12 @@ public class FileOperationService extends Service implements Job.Listener {
 
         String jobId = intent.getStringExtra(EXTRA_JOB_ID);
         @OpType int operationType = intent.getIntExtra(EXTRA_OPERATION, OPERATION_UNKNOWN);
-        checkArgument(jobId != null);
+        assert(jobId != null);
 
         if (intent.hasExtra(EXTRA_CANCEL)) {
             handleCancel(intent);
         } else {
-            checkArgument(operationType != OPERATION_UNKNOWN);
+            assert(operationType != OPERATION_UNKNOWN);
             handleOperation(intent, serviceId, jobId, operationType);
         }
 
@@ -173,9 +170,9 @@ public class FileOperationService extends Service implements Job.Listener {
             mWakeLock.acquire();
         }
 
-        checkState(job != null);
+        assert(job != null);
         int delay = intent.getIntExtra(EXTRA_DELAY, DEFAULT_DELAY);
-        checkArgument(delay <= MAX_DELAY);
+        assert(delay <= MAX_DELAY);
         if (DEBUG) Log.d(
                 TAG, "Scheduling job " + job.id + " to run in " + delay + " milliseconds.");
         ScheduledFuture<?> future = executor.schedule(job, delay, TimeUnit.MILLISECONDS);
@@ -188,8 +185,10 @@ public class FileOperationService extends Service implements Job.Listener {
      * @param intent The cancellation intent.
      */
     private void handleCancel(Intent intent) {
-        checkArgument(intent.hasExtra(EXTRA_CANCEL));
-        String jobId = checkNotNull(intent.getStringExtra(EXTRA_JOB_ID));
+        assert(intent.hasExtra(EXTRA_CANCEL));
+        assert(intent.getStringExtra(EXTRA_JOB_ID) != null);
+
+        String jobId = intent.getStringExtra(EXTRA_JOB_ID);
 
         if (DEBUG) Log.d(TAG, "handleCancel: " + jobId);
 
@@ -253,7 +252,8 @@ public class FileOperationService extends Service implements Job.Listener {
                 throw new UnsupportedOperationException();
         }
 
-        return checkNotNull(job);
+        assert(job != null);
+        return job;
     }
 
     @GuardedBy("mRunning")
@@ -261,7 +261,7 @@ public class FileOperationService extends Service implements Job.Listener {
         if (DEBUG) Log.d(TAG, "deleteJob: " + job.id);
 
         JobRecord record = mRunning.remove(job.id);
-        checkArgument(record != null);
+        assert(record != null);
         record.job.cleanup();
 
         if (mRunning.isEmpty()) {
diff --git a/packages/DocumentsUI/src/com/android/documentsui/services/Job.java b/packages/DocumentsUI/src/com/android/documentsui/services/Job.java
index a15865439f04..c723ac60c334 100644
--- a/packages/DocumentsUI/src/com/android/documentsui/services/Job.java
+++ b/packages/DocumentsUI/src/com/android/documentsui/services/Job.java
@@ -23,8 +23,6 @@ import static com.android.documentsui.services.FileOperationService.EXTRA_JOB_ID
 import static com.android.documentsui.services.FileOperationService.EXTRA_OPERATION;
 import static com.android.documentsui.services.FileOperationService.EXTRA_SRC_LIST;
 import static com.android.documentsui.services.FileOperationService.OPERATION_UNKNOWN;
-import static com.android.internal.util.Preconditions.checkArgument;
-import static com.android.internal.util.Preconditions.checkNotNull;
 
 import android.annotation.DrawableRes;
 import android.annotation.PluralsRes;
@@ -98,7 +96,7 @@ abstract public class Job implements Runnable {
     Job(Context service, Context appContext, Listener listener,
             @OpType int operationType, String id, DocumentStack stack) {
 
-        checkArgument(operationType != OPERATION_UNKNOWN);
+        assert(operationType != OPERATION_UNKNOWN);
 
         this.service = service;
         this.appContext = appContext;
@@ -150,7 +148,8 @@ abstract public class Job implements Runnable {
             mClients.put(doc.authority, client);
         }
 
-        return checkNotNull(client);
+        assert(client != null);
+        return client;
     }
 
     final void cleanup() {
diff --git a/packages/DocumentsUI/src/com/android/documentsui/services/MoveJob.java b/packages/DocumentsUI/src/com/android/documentsui/services/MoveJob.java
index b5826a46ea84..dc39235b35c5 100644
--- a/packages/DocumentsUI/src/com/android/documentsui/services/MoveJob.java
+++ b/packages/DocumentsUI/src/com/android/documentsui/services/MoveJob.java
@@ -21,11 +21,9 @@ import static com.android.documentsui.services.FileOperationService.OPERATION_MO
 import android.app.Notification;
 import android.app.Notification.Builder;
 import android.content.Context;
-import android.net.Uri;
 import android.os.RemoteException;
 import android.provider.DocumentsContract;
 import android.provider.DocumentsContract.Document;
-import android.util.Log;
 
 import com.android.documentsui.R;
 import com.android.documentsui.model.DocumentInfo;
@@ -36,7 +34,6 @@ import java.util.List;
 // TODO: Stop extending CopyJob.
 final class MoveJob extends CopyJob {
 
-    private static final String TAG = "MoveJob";
     final DocumentInfo mSrcParent;
 
     /**