[Reland 2] Pepper takes ownership of a mailbox before passing it to the texture layer.

gpu/ipc/client/command_buffer_proxy_impl.h

Index: gpu/ipc/client/command_buffer_proxy_impl.h
diff --git a/gpu/ipc/client/command_buffer_proxy_impl.h b/gpu/ipc/client/command_buffer_proxy_impl.h
index ddef0d8e8d991c70bd78d8c7356af23366ec6c8a..6c5ed2d1e9e6e45e5c76ecf72506df97930ecce3 100644
--- a/gpu/ipc/client/command_buffer_proxy_impl.h
+++ b/gpu/ipc/client/command_buffer_proxy_impl.h
@@ -116,7 +116,10 @@ class GPU_EXPORT CommandBufferProxyImpl
                        const base::Closure& callback) override;
   bool CanWaitUnverifiedSyncToken(const gpu::SyncToken* sync_token) override;
 
-  bool ProduceFrontBuffer(const gpu::Mailbox& mailbox);
+  void TakeFrontBuffer(const gpu::Mailbox& mailbox);
+  void ReturnFrontBuffer(const gpu::Mailbox& mailbox,
+                         const gpu::SyncToken& sync_token,
+                         bool is_lost);
 
   void AddDeletionObserver(DeletionObserver* observer);
   void RemoveDeletionObserver(DeletionObserver* observer);