Standardize usage of virtual/override/final specifiers in cc/.

cc/input/scroll_elasticity_helper.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 "cc/input/scroll_elasticity_helper.h"
 
 #include "cc/layers/layer_impl.h"
 #include "cc/trees/layer_tree_host_impl.h"
 #include "cc/trees/layer_tree_impl.h"
 
 namespace cc {
 
 class ScrollElasticityHelperImpl : public ScrollElasticityHelper {
  public:
   explicit ScrollElasticityHelperImpl(LayerTreeHostImpl* layer_tree_host_impl);
-  virtual ~ScrollElasticityHelperImpl();
+  ~ScrollElasticityHelperImpl() override;
 
   // The amount that the view is stretched past the normal allowable bounds.
   // The "overhang" amount.
   gfx::Vector2dF StretchAmount() override;
   void SetStretchAmount(const gfx::Vector2dF& stretch_amount) override;
   bool PinnedInDirection(const gfx::Vector2dF& direction) override;
   bool CanScrollHorizontally() override;
   bool CanScrollVertically() override;
   void RequestAnimate() override;
 
@@ skipping 57 matching lines @@
   layer_tree_host_impl_->SetNeedsAnimate();
 }
 
 // static
 ScrollElasticityHelper* ScrollElasticityHelper::CreateForLayerTreeHostImpl(
     LayerTreeHostImpl* layer_tree_host_impl) {
   return new ScrollElasticityHelperImpl(layer_tree_host_impl);
 }
 
 }  // namespace cc