Release resources from SurfaceAggregator when new frame arrives.

The SurfaceAggregator will never need the resources for a frame after a new frame has been submitted for that Surface, so return the resources early.

BUG=441698,441751,440213

Review URL: https://codereview.chromium.org/800133002

Cr-Commit-Position: refs/heads/master@{#308236}

cc/surfaces/display.cc

@@ -169,8 +169,11 @@ void Display::SetMemoryPolicy(const ManagedMemoryPolicy& policy) {
 }
 
 void Display::OnSurfaceDamaged(SurfaceId surface) {
-  if (aggregator_ && aggregator_->previous_contained_surfaces().count(surface))
+  if (aggregator_ &&
+      aggregator_->previous_contained_surfaces().count(surface)) {
+    aggregator_->ReleaseResources(surface);
     client_->DisplayDamaged();
+  }
 }
 
 SurfaceId Display::CurrentSurfaceId() {

cc/surfaces/surface_aggregator.cc

@@ -438,4 +438,13 @@ scoped_ptr<CompositorFrame> SurfaceAggregator::Aggregate(SurfaceId surface_id) {
   return frame.Pass();
 }
 
+void SurfaceAggregator::ReleaseResources(SurfaceId surface_id) {
+  SurfaceToResourceChildIdMap::iterator it =
+      surface_id_to_resource_child_id_.find(surface_id);
+  if (it != surface_id_to_resource_child_id_.end()) {
+    provider_->DestroyChild(it->second);
+    surface_id_to_resource_child_id_.erase(it);
+  }
+}
+
 }  // namespace cc

cc/surfaces/surface_aggregator.h

@@ -32,6 +32,7 @@ class CC_SURFACES_EXPORT SurfaceAggregator {
   ~SurfaceAggregator();
 
   scoped_ptr<CompositorFrame> Aggregate(SurfaceId surface_id);
+  void ReleaseResources(SurfaceId surface_id);
   SurfaceIndexMap& previous_contained_surfaces() {
     return previous_contained_surfaces_;
   }