cc: Without valid frame, delegated renderer layer is not drawable

cc/delegated_renderer_layer.cc

 // Copyright 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "cc/delegated_renderer_layer.h"
 
 #include "cc/delegated_frame_data.h"
 #include "cc/delegated_renderer_layer_impl.h"
 
 namespace cc {
 
 scoped_refptr<DelegatedRendererLayer> DelegatedRendererLayer::Create() {
   return scoped_refptr<DelegatedRendererLayer>(new DelegatedRendererLayer());
 }
 
 DelegatedRendererLayer::DelegatedRendererLayer()
     : Layer() {
 }
 
 DelegatedRendererLayer::~DelegatedRendererLayer() {}
 
 scoped_ptr<LayerImpl> DelegatedRendererLayer::createLayerImpl(
     LayerTreeImpl* tree_impl) {
   return DelegatedRendererLayerImpl::Create(
       tree_impl, m_layerId).PassAs<LayerImpl>();
 }
 
+bool DelegatedRendererLayer::drawsContent() const {
+  return !frame_size_.IsEmpty();
+}
+
 void DelegatedRendererLayer::pushPropertiesTo(LayerImpl* impl) {
   Layer::pushPropertiesTo(impl);
 
   DelegatedRendererLayerImpl* delegated_impl =
       static_cast<DelegatedRendererLayerImpl*>(impl);
 
   delegated_impl->SetDisplaySize(display_size_);
 
-  if (frame_data_)
-    delegated_impl->SetFrameData(frame_data_.Pass(), damage_in_frame_);
-
-  damage_in_frame_ = gfx::RectF();
+  if (frame_data_) {
+    if (frame_size_.IsEmpty()) {
+      scoped_ptr<DelegatedFrameData> empty_frame(new DelegatedFrameData);
+      delegated_impl->SetFrameData(empty_frame.Pass(), gfx::Rect());
+    } else {
+      delegated_impl->SetFrameData(frame_data_.Pass(), damage_in_frame_);
+    }
+    frame_data_.reset();
+    damage_in_frame_ = gfx::RectF();
+  }
 }
 
 void DelegatedRendererLayer::SetDisplaySize(gfx::Size size) {
   if (display_size_ == size)
     return;
   display_size_ = size;
   setNeedsCommit();
 }
 
 void DelegatedRendererLayer::SetFrameData(
     scoped_ptr<DelegatedFrameData> new_frame_data) {
   frame_data_ = new_frame_data.Pass();
   if (!frame_data_->render_pass_list.empty()) {
     RenderPass* root_pass = frame_data_->render_pass_list.back();
     damage_in_frame_.Union(root_pass->damage_rect);
+    frame_size_ = root_pass->output_rect.size();
+  } else {
+    frame_size_ = gfx::Size();
   }
   setNeedsCommit();
 }
 
 }  // namespace cc