Make DrawingBuffer and Canvas2DLayerBridge be cc::TextureLayerClients.

content/renderer/render_thread_impl.cc

Index: content/renderer/render_thread_impl.cc
diff --git a/content/renderer/render_thread_impl.cc b/content/renderer/render_thread_impl.cc
index be2f9b1376bf5c2994b23b544c0bbdf9f6e7081f..ec5a3d833d27e2ff5b7ed67506ff12ce05167d0a 100644
--- a/content/renderer/render_thread_impl.cc
+++ b/content/renderer/render_thread_impl.cc
@@ -37,7 +37,6 @@
 #include "build/build_config.h"
 #include "cc/base/histograms.h"
 #include "cc/base/switches.h"
-#include "cc/blink/web_external_bitmap_impl.h"
 #include "cc/blink/web_layer_impl.h"
 #include "cc/output/buffer_to_texture_target_map.h"
 #include "cc/output/copy_output_request.h"
@@ -317,12 +316,6 @@ void AddHistogramSample(void* hist, int sample) {
   histogram->Add(sample);
 }
 
-std::unique_ptr<cc::SharedBitmap> AllocateSharedBitmapFunction(
-    const gfx::Size& size) {
-  return ChildThreadImpl::current()->shared_bitmap_manager()->
-      AllocateSharedBitmap(size);
-}
-
 void NotifyTimezoneChangeOnThisThread() {
   v8::Isolate* isolate = v8::Isolate::GetCurrent();
   if (!isolate)
@@ -1258,8 +1251,6 @@ void RenderThreadImpl::InitializeWebKit(
           ->renderer()
           ->AllowTimerSuspensionWhenProcessBackgrounded());
 
-  cc_blink::SetSharedBitmapAllocationFunction(AllocateSharedBitmapFunction);
-
   SkGraphics::SetResourceCacheSingleAllocationByteLimit(
       kImageCacheSingleAllocationByteLimit);