Standardize usage of virtual/override/final in cc/

cc/layers/io_surface_layer_impl.h

 // Copyright 2012 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 CC_LAYERS_IO_SURFACE_LAYER_IMPL_H_
 #define CC_LAYERS_IO_SURFACE_LAYER_IMPL_H_
 
 #include <string>
 
 #include "cc/base/cc_export.h"
 #include "cc/layers/layer_impl.h"
 #include "ui/gfx/size.h"
 
 namespace cc {
 
 class CC_EXPORT IOSurfaceLayerImpl : public LayerImpl {
  public:
   static scoped_ptr<IOSurfaceLayerImpl> Create(LayerTreeImpl* tree_impl,
                                                int id) {
     return make_scoped_ptr(new IOSurfaceLayerImpl(tree_impl, id));
   }
-  virtual ~IOSurfaceLayerImpl();
+  ~IOSurfaceLayerImpl() override;
 
   void SetIOSurfaceProperties(unsigned io_surface_id, const gfx::Size& size);
 
-  virtual scoped_ptr<LayerImpl> CreateLayerImpl(LayerTreeImpl* tree_impl)
-      override;
-  virtual void PushPropertiesTo(LayerImpl* layer_tree_impl) override;
+  scoped_ptr<LayerImpl> CreateLayerImpl(LayerTreeImpl* tree_impl) override;
+  void PushPropertiesTo(LayerImpl* layer_tree_impl) override;
 
-  virtual void AppendQuads(RenderPass* render_pass,
-                           const Occlusion& occlusion_in_content_space,
-                           AppendQuadsData* append_quads_data) override;
+  void AppendQuads(RenderPass* render_pass,
+                   const Occlusion& occlusion_in_content_space,
+                   AppendQuadsData* append_quads_data) override;
 
-  virtual bool WillDraw(DrawMode draw_mode,
-                        ResourceProvider* resource_provider) override;
-  virtual void ReleaseResources() override;
+  bool WillDraw(DrawMode draw_mode,
+                ResourceProvider* resource_provider) override;
+  void ReleaseResources() override;
 
  private:
   IOSurfaceLayerImpl(LayerTreeImpl* tree_impl, int id);
 
   void DestroyResource();
 
-  virtual const char* LayerTypeAsString() const override;
+  const char* LayerTypeAsString() const override;
 
   unsigned io_surface_id_;
   gfx::Size io_surface_size_;
   bool io_surface_changed_;
   unsigned io_surface_resource_id_;
 
   DISALLOW_COPY_AND_ASSIGN(IOSurfaceLayerImpl);
 };
 
 }  // namespace cc
 
 #endif  // CC_LAYERS_IO_SURFACE_LAYER_IMPL_H_