Overhaul RenderNode's DisplayList management

* Move mValid to native
* Have destroyHardwareResources destroy everything
* Remove flaky mParentCount checks in setStaging
* All tree updates have an internal observer to
  ensure onRemovedFromTree() is a reliable signal
* onRemovedFromTree() immediately releases resources
  to avoid displaylist "leaks"

Test: Unit tests for validity added & pass, manually
verified that b/34072929 doesn't repro

Bug: 34072929

Change-Id: I856534b4ed1b7f009fc4b7cd13209b97fa42a71c

1 files changed, 4 insertions, 3 deletions

diff --git a/libs/hwui/pipeline/skia/SkiaDisplayList.cpp b/libs/hwui/pipeline/skia/SkiaDisplayList.cpp
index 9db8cd3fe2e2..36d02ecbc8bb 100644
--- a/libs/hwui/pipeline/skia/SkiaDisplayList.cpp
+++ b/libs/hwui/pipeline/skia/SkiaDisplayList.cpp
@@ -51,8 +51,9 @@ void SkiaDisplayList::updateChildren(std::function<void(RenderNode*)> updateFn)
     }
 }
 
-bool SkiaDisplayList::prepareListAndChildren(TreeInfo& info, bool functorsNeedLayer,
-        std::function<void(RenderNode*, TreeInfo&, bool)> childFn) {
+bool SkiaDisplayList::prepareListAndChildren(TreeObserver& observer, TreeInfo& info,
+        bool functorsNeedLayer,
+        std::function<void(RenderNode*, TreeObserver&, TreeInfo&, bool)> childFn) {
     // If the prepare tree is triggered by the UI thread and no previous call to
     // pinImages has failed then we must pin all mutable images in the GPU cache
     // until the next UI thread draw.
@@ -74,7 +75,7 @@ bool SkiaDisplayList::prepareListAndChildren(TreeInfo& info, bool functorsNeedLa
         info.damageAccumulator->pushTransform(&mat4);
         // TODO: a layer is needed if the canvas is rotated or has a non-rect clip
         info.hasBackwardProjectedNodes = false;
-        childFn(childNode, info, functorsNeedLayer);
+        childFn(childNode, observer, info, functorsNeedLayer);
         hasBackwardProjectedNodesSubtree |= info.hasBackwardProjectedNodes;
         info.damageAccumulator->popTransform();
     }