Standardize usage of virtual/override/final specifiers.

ash/touch/touch_hud_debug.cc

Index: ash/touch/touch_hud_debug.cc
diff --git a/ash/touch/touch_hud_debug.cc b/ash/touch/touch_hud_debug.cc
index b714edfc525dad43ef59dbc35e8d7c1eb0b1136b..c7212cf4d3ee1e749975b2110f70c9a827c0ce49 100644
--- a/ash/touch/touch_hud_debug.cc
+++ b/ash/touch/touch_hud_debug.cc
@@ -257,7 +257,7 @@ class TouchHudCanvas : public views::View {
     paint_.setStyle(SkPaint::kFill_Style);
   }
 
-  virtual ~TouchHudCanvas() {}
+  ~TouchHudCanvas() override {}
 
   void SetScale(int scale) {
     if (scale_ == scale)
@@ -308,7 +308,7 @@ class TouchHudCanvas : public views::View {
   }
 
   // Overridden from views::View.
-  virtual void OnPaint(gfx::Canvas* canvas) override {
+  void OnPaint(gfx::Canvas* canvas) override {
     for (int i = 0; i < kMaxPaths; ++i) {
       if (paths_[i].countPoints() == 0)
         continue;