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

services/ui/surfaces/direct_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 "services/ui/surfaces/direct_output_surface.h"
 
 #include <stdint.h>
 
 #include "base/bind.h"
 #include "base/memory/ptr_util.h"
 #include "cc/output/context_provider.h"
 #include "cc/output/output_surface_client.h"
 #include "cc/output/output_surface_frame.h"
 #include "cc/scheduler/begin_frame_source.h"
 #include "gpu/command_buffer/client/context_support.h"
 #include "gpu/command_buffer/client/gles2_interface.h"
 
 namespace ui {
 
 DirectOutputSurface::DirectOutputSurface(
     scoped_refptr<SurfacesContextProvider> context_provider,
     cc::SyntheticBeginFrameSource* synthetic_begin_frame_source)
     : cc::OutputSurface(context_provider),
       synthetic_begin_frame_source_(synthetic_begin_frame_source),
       weak_ptr_factory_(this) {
+  capabilities_.flipped_output_surface =
+      context_provider->ContextCapabilities().flips_vertically;
   context_provider->SetDelegate(this);
 }
 
-DirectOutputSurface::~DirectOutputSurface() = default;
+DirectOutputSurface::~DirectOutputSurface() {}
 
-bool DirectOutputSurface::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 DirectOutputSurface::BindToClient(cc::OutputSurfaceClient* client) {
+  DCHECK(client);
+  DCHECK(!client_);
+  client_ = client;
 }
 
 void DirectOutputSurface::EnsureBackbuffer() {}
 
 void DirectOutputSurface::DiscardBackbuffer() {
   context_provider()->ContextGL()->DiscardBackbufferCHROMIUM();
 }
 
 void DirectOutputSurface::BindFramebuffer() {
   context_provider()->ContextGL()->BindFramebuffer(GL_FRAMEBUFFER, 0);
@@ skipping 64 matching lines @@
   synthetic_begin_frame_source_->OnUpdateVSyncParameters(
       timebase,
       interval.is_zero() ? cc::BeginFrameArgs::DefaultInterval() : interval);
 }
 
 void DirectOutputSurface::OnSwapBuffersComplete() {
   client_->DidReceiveSwapBuffersAck();
 }
 
 }  // namespace ui