cc: Unused resources should be given back to the child compositor

cc/delegated_renderer_layer.cc

Index: cc/delegated_renderer_layer.cc
diff --git a/cc/delegated_renderer_layer.cc b/cc/delegated_renderer_layer.cc
index 7e06e4fc52938ec8b6320040cee530b262caf852..297a5e894573fdfd772259937c17eb0b57958cf8 100644
--- a/cc/delegated_renderer_layer.cc
+++ b/cc/delegated_renderer_layer.cc
@@ -37,10 +37,11 @@ void DelegatedRendererLayer::pushPropertiesTo(LayerImpl* impl) {
 
   delegated_impl->SetDisplaySize(display_size_);
 
-  if (!frame_data_)
-    return;
-
-  if (frame_size_.IsEmpty()) {
+  if (!frame_data_) {
+    delegated_impl->SetFrameData(scoped_ptr<DelegatedFrameData>(),
+                                 gfx::Rect(),
+                                 &unused_resources_for_child_compositor_);
+  } else if (frame_size_.IsEmpty()) {
     scoped_ptr<DelegatedFrameData> empty_frame(new DelegatedFrameData);
     delegated_impl->SetFrameData(empty_frame.Pass(),
                                  gfx::Rect(),
@@ -75,6 +76,16 @@ void DelegatedRendererLayer::SetFrameData(
     RenderPass* root_pass = frame_data_->render_pass_list.back();
     damage_in_frame_.Union(root_pass->damage_rect);
     frame_size_ = root_pass->output_rect.size();
+
+    // TODO(danakj): This could be optimized to only add resources to the
+    // frame_data_ if they are actually used in the frame. For now, it will
+    // cause the parent (this layer) to hold onto some resources it doesn't
+    // need to for an extra frame.
+    for (size_t i = 0; i < unused_resources_for_child_compositor_.size(); ++i) {
+      frame_data_->resource_list.push_back(
+          unused_resources_for_child_compositor_[i]);
+    }
+    unused_resources_for_child_compositor_.clear();
   } else {
     frame_size_ = gfx::Size();
   }