Cleanup GpuMemoryBuffer

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 ad56d18d85a13aca16672a2eb0d79794a3808277..17c9cca2dde224a07578f20d9ea81fd865e0bf44 100644
--- a/content/common/gpu/client/gpu_channel_host.h
+++ b/content/common/gpu/client/gpu_channel_host.h
@@ -75,6 +75,8 @@ class CONTENT_EXPORT GpuChannelHostFactory {
       int32 surface_id,
       const GPUCreateCommandBufferConfig& init_params,
       int32 route_id) = 0;
+  virtual void WaitForPendingGpuMemoryBufferUsageToComplete(
+      const base::Closure& callback) = 0;
 };
 
 // Encapsulates an IPC channel between the client and one GPU process.
@@ -161,6 +163,9 @@ class GpuChannelHost : public IPC::Sender,
   // Generate a route ID guaranteed to be unique for this channel.
   int32 GenerateRouteID();
 
+  void WaitForPendingGpuMemoryBufferUsageToComplete(
+      const base::Closure& callback);
+
  private:
   friend class base::RefCountedThreadSafe<GpuChannelHost>;
   GpuChannelHost(GpuChannelHostFactory* factory,