gpu: Remove Echo and SwapCompletion GL interfacess

ppapi/proxy/ppapi_command_buffer_proxy.h

 // Copyright (c) 2012 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 PPAPI_PROXY_COMMAND_BUFFER_PROXY_H_
 #define PPAPI_PROXY_COMMAND_BUFFER_PROXY_H_
 
 #include "base/callback.h"
 #include "base/containers/hash_tables.h"
 #include "base/memory/scoped_ptr.h"
@@ skipping 42 matching lines @@
                                                       int32* id) OVERRIDE;
   virtual void DestroyGpuMemoryBuffer(int32 id) OVERRIDE;
   virtual uint32 InsertSyncPoint() OVERRIDE;
   virtual uint32 InsertFutureSyncPoint() OVERRIDE;
   virtual void RetireSyncPoint(uint32 sync_point) OVERRIDE;
   virtual void SignalSyncPoint(uint32 sync_point,
                                const base::Closure& callback) OVERRIDE;
   virtual void SignalQuery(uint32 query,
                            const base::Closure& callback) OVERRIDE;
   virtual void SetSurfaceVisible(bool visible) OVERRIDE;
-  virtual void Echo(const base::Closure& callback) OVERRIDE;
   virtual uint32 CreateStreamTexture(uint32 texture_id) OVERRIDE;
 
  private:
   bool Send(IPC::Message* msg);
   void UpdateState(const gpu::CommandBuffer::State& state, bool success);
 
   // Try to read an updated copy of the state from shared memory.
   void TryUpdateState();
 
   // The shared memory area used to update state.
   gpu::CommandBufferSharedState* shared_state() const;
 
   State last_state_;
   scoped_ptr<base::SharedMemory> shared_state_shm_;
 
   HostResource resource_;
   ProxyChannel* channel_;
 
   base::Closure channel_error_callback_;
 
   DISALLOW_COPY_AND_ASSIGN(PpapiCommandBufferProxy);
 };
 
 }  // namespace proxy
 }  // namespace ppapi
 
 #endif // PPAPI_PROXY_COMMAND_BUFFER_PROXY_H_