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

android_webview/browser/surfaces_instance.h

 // 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.
 
 #ifndef ANDROID_WEBVIEW_BROWSER_SURFACES_INSTANCE_H_
 #define ANDROID_WEBVIEW_BROWSER_SURFACES_INSTANCE_H_
 
 #include <memory>
 #include <vector>
 
@@ skipping 40 matching lines @@
   void AddChildId(const cc::SurfaceId& child_id);
   void RemoveChildId(const cc::SurfaceId& child_id);
 
  private:
   friend class base::RefCounted<SurfacesInstance>;
 
   SurfacesInstance();
   ~SurfacesInstance() override;
 
   // cc::DisplayClient overrides.
-  void DisplayOutputSurfaceLost() override {}
+  void DisplayOutputSurfaceLost() override;
   void DisplayWillDrawAndSwap(
       bool will_draw_and_swap,
       const cc::RenderPassList& render_passes) override {}
   void DisplayDidDrawAndSwap() override {}
 
   // cc::SurfaceFactoryClient implementation.
   void ReturnResources(const cc::ReturnedResourceArray& resources) override;
   void SetBeginFrameSource(cc::BeginFrameSource* begin_frame_source) override;
 
   void SetEmptyRootFrame();
@@ skipping 12 matching lines @@
 
   // This is owned by |display_|.
   ParentOutputSurface* output_surface_;
 
   DISALLOW_COPY_AND_ASSIGN(SurfacesInstance);
 };
 
 }  // namespace android_webview
 
 #endif  // ANDROID_WEBVIEW_BROWSER_SURFACES_INSTANCE_H_