Clean up Mac swap acknowledgement code

content/browser/compositor/reflector_impl_unittest.cc

 // Copyright 2015 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 "base/run_loop.h"
 #include "base/single_thread_task_runner.h"
 #include "cc/test/fake_output_surface_client.h"
 #include "cc/test/test_context_provider.h"
 #include "cc/test/test_web_graphics_context_3d.h"
 #include "content/browser/compositor/browser_compositor_output_surface.h"
@@ skipping 76 matching lines @@
 
   void OnReflectorChanged() override {
     if (!reflector_) {
       reflector_texture_.reset();
     } else {
       reflector_texture_.reset(new ReflectorTexture(context_provider()));
       reflector_->OnSourceTextureMailboxUpdated(reflector_texture_->mailbox());
     }
   }
 
+  void OnGpuSwapBuffersCompleted(
+      const std::vector<ui::LatencyInfo>& latency_info,
+      gfx::SwapResult result) override {
+    NOTREACHED();
+  }
+
 #if defined(OS_MACOSX)
-  void OnSurfaceDisplayed() override {}
   void SetSurfaceSuspendedForRecycle(bool suspended) override {}
   bool SurfaceShouldNotShowFramesAfterSuspendForRecycle() const override {
     return false;
   }
 #endif
 
  private:
   scoped_ptr<ReflectorTexture> reflector_texture_;
 };
 
@@ skipping 106 matching lines @@
   plane_2.plane_z_order = 1;
   list.push_back(plane_1);
   list.push_back(plane_2);
   output_surface_->GetOverlayCandidateValidator()->CheckOverlaySupport(&list);
   EXPECT_FALSE(list[0].overlay_handled);
 }
 #endif  // defined(USE_OZONE)
 
 }  // namespace
 }  // namespace content