cc: Make OutputSurface::BindToClient pure virtual and not return bool

services/ui/surfaces/direct_output_surface_ozone.cc

 // 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.
 
 #include "services/ui/surfaces/direct_output_surface_ozone.h"
 
 #include <utility>
 
 #include "base/bind.h"
 #include "base/memory/ptr_util.h"
@@ skipping 43 matching lines @@
 
   context_provider->SetSwapBuffersCompletionCallback(
       base::Bind(&DirectOutputSurfaceOzone::OnGpuSwapBuffersCompleted,
                  base::Unretained(this)));
 }
 
 DirectOutputSurfaceOzone::~DirectOutputSurfaceOzone() {
   // TODO(rjkroege): Support cleanup.
 }
 
-bool DirectOutputSurfaceOzone::BindToClient(cc::OutputSurfaceClient* client) {
-  if (!cc::OutputSurface::BindToClient(client))
-    return false;
-
-  if (capabilities_.uses_default_gl_framebuffer) {
-    capabilities_.flipped_output_surface =
-        context_provider()->ContextCapabilities().flips_vertically;
-  }
-  return true;
+void DirectOutputSurfaceOzone::BindToClient(cc::OutputSurfaceClient* client) {
+  DCHECK(client);
+  DCHECK(!client_);
+  client_ = client;
 }
 
 void DirectOutputSurfaceOzone::EnsureBackbuffer() {}
 
 void DirectOutputSurfaceOzone::DiscardBackbuffer() {
   context_provider()->ContextGL()->DiscardBackbufferCHROMIUM();
 }
 
 void DirectOutputSurfaceOzone::BindFramebuffer() {
   DCHECK(buffer_queue_);
@@ skipping 89 matching lines @@
   }
 
   buffer_queue_->PageFlipComplete();
   client_->DidReceiveSwapBuffersAck();
 
   if (force_swap)
     client_->SetNeedsRedrawRect(gfx::Rect(swap_size_));
 }
 
 }  // namespace ui