Add gfx::GpuMemoryBuffer::YUV_420 and GpuMemoryBufferImplSharedMemory support

content/common/gpu/client/gpu_memory_buffer_impl.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 CONTENT_COMMON_GPU_CLIENT_GPU_MEMORY_BUFFER_IMPL_H_
 #define CONTENT_COMMON_GPU_CLIENT_GPU_MEMORY_BUFFER_IMPL_H_
 
 #include "base/callback.h"
 #include "base/memory/scoped_ptr.h"
 #include "content/common/content_export.h"
@@ skipping 15 matching lines @@
   // thread as this function was called on and instance was created on.
   static scoped_ptr<GpuMemoryBufferImpl> CreateFromHandle(
       const gfx::GpuMemoryBufferHandle& handle,
       const gfx::Size& size,
       Format format,
       const DestructionCallback& callback);
 
   // Type-checking upcast routine. Returns an NULL on failure.
   static GpuMemoryBufferImpl* FromClientBuffer(ClientBuffer buffer);
 
+  // Returns the number of planes based on the format of the buffer.
+  static size_t NumberOfPlanesForGpuMemoryBufferFormat(Format format);
+
   // Calculates the number of bytes that an implementation must use to store
   // one row of pixel data.
   static bool StrideInBytes(size_t width,
                             Format format,
+                            int plane,
                             size_t* stride_in_bytes);
 
-  // Returns the number of planes based on the format of the buffer.
-  static size_t NumberOfPlanesForGpuMemoryBufferFormat(
-      gfx::GpuMemoryBuffer::Format format);
+  // Returns the subsampling factor applied to the given zero-indexed |plane| of
+  // the |format| both horizontally and vertically.
+  static size_t SubsamplingFactor(Format format, int plane);
 
   // Overridden from gfx::GpuMemoryBuffer:
   bool IsMapped() const override;
   Format GetFormat() const override;
   ClientBuffer AsClientBuffer() override;
 
   void set_destruction_sync_point(uint32 sync_point) {
     destruction_sync_point_ = sync_point;
   }
 
@@ skipping 10 matching lines @@
   bool mapped_;
   uint32 destruction_sync_point_;
 
  private:
   DISALLOW_COPY_AND_ASSIGN(GpuMemoryBufferImpl);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_COMMON_GPU_CLIENT_GPU_MEMORY_BUFFER_IMPL_H_