Plumb GpuMemoryBuffer allocation to GPU process.

content/common/gpu/client/gpu_channel_host.h

Index: content/common/gpu/client/gpu_channel_host.h
diff --git a/content/common/gpu/client/gpu_channel_host.h b/content/common/gpu/client/gpu_channel_host.h
index 4f5b74f010d3ad22d4ee963a1751d5cf4ace05b1..6d5412db40a23a04220652351643cef903227f91 100644
--- a/content/common/gpu/client/gpu_channel_host.h
+++ b/content/common/gpu/client/gpu_channel_host.h
@@ -62,6 +62,9 @@ class CONTENT_EXPORT GpuChannelHostFactory {
  public:
   typedef base::Callback<void(const gfx::Size)> CreateImageCallback;
 
+  typedef base::Callback<void(const gfx::GpuMemoryBufferHandle& handle)>
+      AllocateGpuMemoryBufferCallback;
+
   virtual ~GpuChannelHostFactory() {}
 
   virtual bool IsMainThread() = 0;
@@ -82,6 +85,9 @@ class CONTENT_EXPORT GpuChannelHostFactory {
       size_t height,
       unsigned internalformat,
       unsigned usage) = 0;
+  virtual void AllocateGpuMemoryBufferAsync(
+      const gfx::GpuMemoryBufferParams& params,
+      const AllocateGpuMemoryBufferCallback& callback) = 0;
 };
 
 // Encapsulates an IPC channel between the client and one GPU process.