Release resources from SurfaceAggregator when new frame arrives.

cc/surfaces/display.cc

Index: cc/surfaces/display.cc
diff --git a/cc/surfaces/display.cc b/cc/surfaces/display.cc
index 3aba574846c1e2eb0a2c88b4588d25ec24cf9d77..8833037c5ecbd822fc554b6697657c59b474739e 100644
--- a/cc/surfaces/display.cc
+++ b/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);

[jamesr, 2014/12/13 01:54:26]

it's a little fragile here that we have to make sure we take refs on incoming
resources before notifying the display that it's damaged, or we might release a
resource that we really wanted (iiuc).  I don't really have a great better idea
though.

     client_->DisplayDamaged();
+  }
 }
 
 SurfaceId Display::CurrentSurfaceId() {