gpu: Remove Echo and SwapCompletion GL interfacess

gpu/command_buffer/client/context_support.h

 // Copyright 2013 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 GPU_COMMAND_BUFFER_CLIENT_CONTEXT_SUPPORT_H_
 #define GPU_COMMAND_BUFFER_CLIENT_CONTEXT_SUPPORT_H_
 
 #include "base/callback.h"
 #include "ui/gfx/overlay_transform.h"
 #include "ui/gfx/rect.h"
@@ skipping 10 matching lines @@
   // passed the glEndQueryEXT() point.
   virtual void SignalQuery(uint32 query, const base::Closure& callback) = 0;
 
   // For onscreen contexts, indicates that the surface visibility has changed.
   // Clients aren't expected to draw to an invisible surface.
   virtual void SetSurfaceVisible(bool visible) = 0;
 
   virtual void Swap() = 0;
   virtual void PartialSwapBuffers(const gfx::Rect& sub_buffer) = 0;
 
-  virtual void SetSwapBuffersCompleteCallback(
-      const base::Closure& callback) = 0;
-
   // Schedule a texture to be presented as an overlay synchronously with the
   // primary surface during the next buffer swap.
   // This method is not stateful and needs to be re-scheduled every frame.
   virtual void ScheduleOverlayPlane(int plane_z_order,
                                     gfx::OverlayTransform plane_transform,
                                     unsigned overlay_texture_id,
                                     const gfx::Rect& display_bounds,
                                     const gfx::RectF& uv_rect) = 0;
 
   virtual uint32 InsertFutureSyncPointCHROMIUM() = 0;
   virtual void RetireSyncPointCHROMIUM(uint32 sync_point) = 0;
 
  protected:
   ContextSupport() {}
   virtual ~ContextSupport() {}
 };
 
 }
 
 #endif  // GPU_COMMAND_BUFFER_CLIENT_CONTEXT_SUPPORT_H_