cc: Add mailbox support to ResourceProvider write locks.

cc/raster/zero_copy_raster_buffer_provider.h

 // Copyright 2013 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.
 
 #ifndef CC_RASTER_ZERO_COPY_RASTER_BUFFER_PROVIDER_H_
 #define CC_RASTER_ZERO_COPY_RASTER_BUFFER_PROVIDER_H_
 
 #include <stdint.h>
 
 #include "base/macros.h"
@@ skipping 17 matching lines @@
   static std::unique_ptr<RasterBufferProvider> Create(
       ResourceProvider* resource_provider,
       ResourceFormat preferred_tile_format);
 
   // Overridden from RasterBufferProvider:
   std::unique_ptr<RasterBuffer> AcquireBufferForRaster(
       const Resource* resource,
       uint64_t resource_content_id,
       uint64_t previous_content_id) override;
   void ReleaseBufferForRaster(std::unique_ptr<RasterBuffer> buffer) override;
-  void OrderingBarrier() override;
+  bool OrderingBarrier() override;
   ResourceFormat GetResourceFormat(bool must_support_alpha) const override;
   bool GetResourceRequiresSwizzle(bool must_support_alpha) const override;
   void Shutdown() override;
 
  protected:
   ZeroCopyRasterBufferProvider(ResourceProvider* resource_provider,
                                ResourceFormat preferred_tile_format);
 
  private:
   std::unique_ptr<base::trace_event::ConvertableToTraceFormat> StateAsValue()
       const;
 
   ResourceProvider* resource_provider_;
   ResourceFormat preferred_tile_format_;
 
   DISALLOW_COPY_AND_ASSIGN(ZeroCopyRasterBufferProvider);
 };
 
 }  // namespace cc
 
 #endif  // CC_RASTER_ZERO_COPY_RASTER_BUFFER_PROVIDER_H_