Update from https://crrev.com/304121

cc/trees/layer_tree_host.cc

Index: cc/trees/layer_tree_host.cc
diff --git a/cc/trees/layer_tree_host.cc b/cc/trees/layer_tree_host.cc
index af7eb5bc96e62fe8692b3f459714d06c7017088d..f85d4e7bc00fdcb0475ce77741c52eb5785a6358 100644
--- a/cc/trees/layer_tree_host.cc
+++ b/cc/trees/layer_tree_host.cc
@@ -32,6 +32,7 @@
 #include "cc/layers/render_surface.h"
 #include "cc/resources/prioritized_resource_manager.h"
 #include "cc/resources/ui_resource_request.h"
+#include "cc/scheduler/begin_frame_source.h"
 #include "cc/trees/layer_tree_host_client.h"
 #include "cc/trees/layer_tree_host_common.h"
 #include "cc/trees/layer_tree_host_impl.h"
@@ -71,12 +72,15 @@ scoped_ptr<LayerTreeHost> LayerTreeHost::CreateThreaded(
     gpu::GpuMemoryBufferManager* gpu_memory_buffer_manager,
     const LayerTreeSettings& settings,
     scoped_refptr<base::SingleThreadTaskRunner> main_task_runner,
-    scoped_refptr<base::SingleThreadTaskRunner> impl_task_runner) {
+    scoped_refptr<base::SingleThreadTaskRunner> impl_task_runner,
+    scoped_ptr<BeginFrameSource> external_begin_frame_source) {
   DCHECK(main_task_runner.get());
   DCHECK(impl_task_runner.get());
   scoped_ptr<LayerTreeHost> layer_tree_host(new LayerTreeHost(
       client, shared_bitmap_manager, gpu_memory_buffer_manager, settings));
-  layer_tree_host->InitializeThreaded(main_task_runner, impl_task_runner);
+  layer_tree_host->InitializeThreaded(main_task_runner,
+                                      impl_task_runner,
+                                      external_begin_frame_source.Pass());
   return layer_tree_host.Pass();
 }
 
@@ -86,11 +90,13 @@ scoped_ptr<LayerTreeHost> LayerTreeHost::CreateSingleThreaded(
     SharedBitmapManager* shared_bitmap_manager,
     gpu::GpuMemoryBufferManager* gpu_memory_buffer_manager,
     const LayerTreeSettings& settings,
-    scoped_refptr<base::SingleThreadTaskRunner> main_task_runner) {
+    scoped_refptr<base::SingleThreadTaskRunner> main_task_runner,
+    scoped_ptr<BeginFrameSource> external_begin_frame_source) {
   scoped_ptr<LayerTreeHost> layer_tree_host(new LayerTreeHost(
       client, shared_bitmap_manager, gpu_memory_buffer_manager, settings));
   layer_tree_host->InitializeSingleThreaded(single_thread_client,
-                                            main_task_runner);
+                                            main_task_runner,
+                                            external_begin_frame_source.Pass());
   return layer_tree_host.Pass();
 }
 
@@ -139,16 +145,23 @@ LayerTreeHost::LayerTreeHost(
 
 void LayerTreeHost::InitializeThreaded(
     scoped_refptr<base::SingleThreadTaskRunner> main_task_runner,
-    scoped_refptr<base::SingleThreadTaskRunner> impl_task_runner) {
-  InitializeProxy(
-      ThreadProxy::Create(this, main_task_runner, impl_task_runner));
+    scoped_refptr<base::SingleThreadTaskRunner> impl_task_runner,
+    scoped_ptr<BeginFrameSource> external_begin_frame_source) {
+  InitializeProxy(ThreadProxy::Create(this,
+                                      main_task_runner,
+                                      impl_task_runner,
+                                      external_begin_frame_source.Pass()));
 }
 
 void LayerTreeHost::InitializeSingleThreaded(
     LayerTreeHostSingleThreadClient* single_thread_client,
-    scoped_refptr<base::SingleThreadTaskRunner> main_task_runner) {
+    scoped_refptr<base::SingleThreadTaskRunner> main_task_runner,
+    scoped_ptr<BeginFrameSource> external_begin_frame_source) {
   InitializeProxy(
-      SingleThreadProxy::Create(this, single_thread_client, main_task_runner));
+      SingleThreadProxy::Create(this,
+                                single_thread_client,
+                                main_task_runner,
+                                external_begin_frame_source.Pass()));
 }
 
 void LayerTreeHost::InitializeForTesting(scoped_ptr<Proxy> proxy_for_testing) {
@@ -960,7 +973,6 @@ void LayerTreeHost::PrioritizeTextures(
 size_t LayerTreeHost::CalculateMemoryForRenderSurfaces(
     const RenderSurfaceLayerList& update_list) {
   size_t readback_bytes = 0;
-  size_t max_background_texture_bytes = 0;
   size_t contents_texture_bytes = 0;
 
   // Start iteration at 1 to skip the root surface as it does not have a texture
@@ -974,17 +986,16 @@ size_t LayerTreeHost::CalculateMemoryForRenderSurfaces(
                                   RGBA_8888);
     contents_texture_bytes += bytes;
 
-    if (render_surface_layer->background_filters().IsEmpty())
+    if (render_surface_layer->background_filters().IsEmpty() &&
+        render_surface_layer->uses_default_blend_mode())
       continue;
 
-    if (bytes > max_background_texture_bytes)
-      max_background_texture_bytes = bytes;
     if (!readback_bytes) {
       readback_bytes = Resource::MemorySizeBytes(device_viewport_size_,
                                                  RGBA_8888);
     }
   }
-  return readback_bytes + max_background_texture_bytes + contents_texture_bytes;
+  return readback_bytes + contents_texture_bytes;
 }
 
 void LayerTreeHost::PaintMasksForRenderSurface(Layer* render_surface_layer,