cc: Remove OutputSurfaceClient::DidSwapBuffers().

cc/test/pixel_test_output_surface.cc

 // 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.
 
 #include "cc/test/pixel_test_output_surface.h"
 
 #include <utility>
 
 #include "cc/output/compositor_frame.h"
 #include "cc/output/output_surface_client.h"
@@ skipping 36 matching lines @@
                           size.height() + surface_expansion_size_.height());
   OutputSurface::Reshape(expanded_size, scale_factor, color_space, has_alpha);
 }
 
 bool PixelTestOutputSurface::HasExternalStencilTest() const {
   return external_stencil_test_;
 }
 
 void PixelTestOutputSurface::SwapBuffers(CompositorFrame frame) {
   PostSwapBuffersComplete();
-  client_->DidSwapBuffers();
 }
 
 uint32_t PixelTestOutputSurface::GetFramebufferCopyTextureFormat() {
   // This format will work if the |context_provider| has an RGB or RGBA
   // framebuffer. For now assume tests do not want/care about alpha in
   // the root render pass.
   return GL_RGB;
 }
 
 }  // namespace cc