cc: Implement shared worker contexts.

content/common/gpu/client/command_buffer_proxy_impl.h

Index: content/common/gpu/client/command_buffer_proxy_impl.h
diff --git a/content/common/gpu/client/command_buffer_proxy_impl.h b/content/common/gpu/client/command_buffer_proxy_impl.h
index 82e30e5632fca5ce933aff04333215f24cf90780..fa4cdc722f5cdc4c581f86f5320174ce3423a0d4 100644
--- a/content/common/gpu/client/command_buffer_proxy_impl.h
+++ b/content/common/gpu/client/command_buffer_proxy_impl.h
@@ -67,6 +67,8 @@ class CommandBufferProxyImpl
                          int32 stream_id);
   ~CommandBufferProxyImpl() override;
 
+  void Destroy();
+
   // Sends an IPC message to create a GpuVideoDecodeAccelerator. Creates and
   // returns it as an owned pointer to a media::VideoDecodeAccelerator.  Returns
   // NULL on failure to create the GpuVideoDecodeAcceleratorHost.
@@ -165,6 +167,8 @@ class CommandBufferProxyImpl
     return shared_state_shm_->handle();
   }
 
+  base::Lock* lock() { return lock_; }
+
  private:
   typedef std::map<int32, scoped_refptr<gpu::Buffer> > TransferBufferMap;
   typedef base::hash_map<uint32, base::Closure> SignalTaskMap;