Make Mac swap code like other platforms

components/mus/gpu/gpu_service_mus.h

 // Copyright 2016 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 COMPONENTS_MUS_GPU_GPU_SERVICE_MUS_H_
 #define COMPONENTS_MUS_GPU_GPU_SERVICE_MUS_H_
 
 #include "gpu/ipc/common/surface_handle.h"
 #include "gpu/ipc/service/gpu_channel_manager_delegate.h"
 
@@ skipping 11 matching lines @@
   void DidCreateOffscreenContext(const GURL& active_url) override;
   void DidDestroyChannel(int client_id) override;
   void DidDestroyOffscreenContext(const GURL& active_url) override;
   void DidLoseContext(bool offscreen,
                       gpu::error::ContextLostReason reason,
                       const GURL& active_url) override;
   void GpuMemoryUmaStats(const gpu::GPUMemoryUmaStats& params) override;
   void StoreShaderToDisk(int32_t client_id,
                          const std::string& key,
                          const std::string& shader) override;
-#if defined(OS_MACOSX)
-  void SendAcceleratedSurfaceBuffersSwapped(
-      gpu::SurfaceHandle surface_handle,
-      CAContextID ca_context_id,
-      const gfx::ScopedRefCountedIOSurfaceMachPort& io_surface,
-      const gfx::Size& size,
-      float scale_factor,
-      std::vector<ui::LatencyInfo> latency_info) override;
-#endif
 #if defined(OS_WIN)
   void SendAcceleratedSurfaceCreatedChildWindow(
       gpu::SurfaceHandle parent_window,
       gpu::SurfaceHandle child_window) override;
 #endif
   void SetActiveURL(const GURL& url) override;
 
  private:
   DISALLOW_COPY_AND_ASSIGN(GpuServiceMus);
 };
 
 }  // namespace mus
 
 #endif  // COMPONENTS_MUS_GPU_GPU_SERVICE_MUS_H_