Standardize usage of virtual/override/final specifiers.

ash/wm/overview/window_selector_panels.cc

Index: ash/wm/overview/window_selector_panels.cc
diff --git a/ash/wm/overview/window_selector_panels.cc b/ash/wm/overview/window_selector_panels.cc
index 89f8fe6017dfb6d7467b88d505d06f7c53a48c95..e2d3e8cd9207bfd28893b654bf743f9eca56653b 100644
--- a/ash/wm/overview/window_selector_panels.cc
+++ b/ash/wm/overview/window_selector_panels.cc
@@ -27,15 +27,14 @@ namespace {
 class ScopedTransformPanelWindow : public ScopedTransformOverviewWindow {
  public:
   explicit ScopedTransformPanelWindow(aura::Window* window);
-  virtual ~ScopedTransformPanelWindow();
+  ~ScopedTransformPanelWindow() override;
 
   // ScopedTransformOverviewWindow overrides:
-  virtual void PrepareForOverview() override;
+  void PrepareForOverview() override;
 
-  virtual void SetTransform(
-      aura::Window* root_window,
-      const gfx::Transform& transform,
-      bool animate) override;
+  void SetTransform(aura::Window* root_window,
+                    const gfx::Transform& transform,
+                    bool animate) override;
 
  private:
   // Returns the panel window bounds after the transformation.