Remove dependency to libmediadrm from drm HAL

drm HAL has been using libmediadrm for android::SharedLibrary class and
android::PluginLoader class. This is a Treble violation since
libmediadrm is a framework-only library that is not available to
vendors.

To solve the problem, the two classes are copied into this directory
to form a small static library android.hardware.drm@1.0-helper.a.

Bug: 38302533
Test: mm under /hardware/interfaces/drm/1.0/default and
/hardware/interfaces/drm/1.0/vts/functional

Change-Id: I7b4e5cdb3bc815e971e0c3b7ec99ea86042e13eb

1 files changed, 63 insertions, 0 deletions

diff --git a/drm/1.0/default/SharedLibrary.cpp b/drm/1.0/default/SharedLibrary.cpp
new file mode 100644
index 0000000000..0a942cddeb
--- /dev/null
+++ b/drm/1.0/default/SharedLibrary.cpp
@@ -0,0 +1,63 @@
+/*
+ * Copyright (C) 2017 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+
+#include "SharedLibrary.h"
+
+#include <dlfcn.h>
+
+namespace android {
+namespace hardware {
+namespace drm {
+namespace V1_0 {
+namespace helper {
+
+SharedLibrary::SharedLibrary(const String8& path) {
+    mLibHandle = dlopen(path.string(), RTLD_NOW);
+}
+
+SharedLibrary::~SharedLibrary() {
+    if (mLibHandle != NULL) {
+        dlclose(mLibHandle);
+        mLibHandle = NULL;
+    }
+}
+
+bool SharedLibrary::operator!() const {
+    return mLibHandle == NULL;
+}
+
+void* SharedLibrary::lookup(const char* symbol) const {
+    if (!mLibHandle) {
+        return NULL;
+    }
+
+    // Clear last error before we load the symbol again,
+    // in case the caller didn't retrieve it.
+    (void)dlerror();
+    return dlsym(mLibHandle, symbol);
+}
+
+const char* SharedLibrary::lastError() const {
+    const char* error = dlerror();
+    return error ? error : "No errors or unknown error";
+}
+
+}
+}
+}
+}
+} // namespace android