Clean up Mac swap acknowledgement code

content/browser/compositor/gpu_surfaceless_browser_compositor_output_surface.cc

 // Copyright 2014 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.
 
 #include "content/browser/compositor/gpu_surfaceless_browser_compositor_output_surface.h"
 
 #include "cc/output/compositor_frame.h"
 #include "cc/output/output_surface_client.h"
 #include "content/browser/compositor/browser_compositor_overlay_candidate_validator.h"
 #include "content/browser/compositor/buffer_queue.h"
@@ skipping 75 matching lines @@
 }
 
 void GpuSurfacelessBrowserCompositorOutputSurface::Reshape(
     const gfx::Size& size,
     float scale_factor) {
   GpuBrowserCompositorOutputSurface::Reshape(size, scale_factor);
   DCHECK(output_surface_);
   output_surface_->Reshape(SurfaceSize(), scale_factor);
 }
 
-void GpuSurfacelessBrowserCompositorOutputSurface::OnSwapBuffersCompleted(
+void GpuSurfacelessBrowserCompositorOutputSurface::OnGpuSwapBuffersCompleted(
     const std::vector<ui::LatencyInfo>& latency_info,
     gfx::SwapResult result) {
-#if defined(OS_MACOSX)
-  NOTREACHED();
-#else
   bool force_swap = false;
   if (result == gfx::SwapResult::SWAP_NAK_RECREATE_BUFFERS) {
     // Even through the swap failed, this is a fixable error so we can pretend
     // it succeeded to the rest of the system.
     result = gfx::SwapResult::SWAP_ACK;
     output_surface_->RecreateBuffers();
     force_swap = true;
   }
-  GpuBrowserCompositorOutputSurface::OnSwapBuffersCompleted(latency_info,
-                                                            result);
+  GpuBrowserCompositorOutputSurface::OnGpuSwapBuffersCompleted(latency_info,
+                                                               result);
   if (force_swap)
     client_->SetNeedsRedrawRect(gfx::Rect(SurfaceSize()));
-#endif
 }
 
-#if defined(OS_MACOSX)
-void GpuSurfacelessBrowserCompositorOutputSurface::OnSurfaceDisplayed() {
-  OnSwapBuffersComplete();
-}
-#endif
-
 }  // namespace content