Standardize usage of virtual/override/final in chrome/browser/

chrome/browser/themes/theme_service.h

Index: chrome/browser/themes/theme_service.h
diff --git a/chrome/browser/themes/theme_service.h b/chrome/browser/themes/theme_service.h
index 2bfed249429a4fa7d9908bab897d4ccf47c2e790..c6135abe9e3086ad0f1ae856e08cbca4664cc5f0 100644
--- a/chrome/browser/themes/theme_service.h
+++ b/chrome/browser/themes/theme_service.h
@@ -65,7 +65,7 @@ class ThemeService : public base::NonThreadSafe,
   static const char* kDefaultThemeID;
 
   ThemeService();
-  virtual ~ThemeService();
+  ~ThemeService() override;
 
   virtual void Init(Profile* profile);
 
@@ -76,27 +76,26 @@ class ThemeService : public base::NonThreadSafe,
   virtual gfx::Image GetImageNamed(int id) const;
 
   // Overridden from ui::ThemeProvider:
-  virtual bool UsingSystemTheme() const override;
-  virtual gfx::ImageSkia* GetImageSkiaNamed(int id) const override;
-  virtual SkColor GetColor(int id) const override;
-  virtual int GetDisplayProperty(int id) const override;
-  virtual bool ShouldUseNativeFrame() const override;
-  virtual bool HasCustomImage(int id) const override;
-  virtual base::RefCountedMemory* GetRawData(
-      int id,
-      ui::ScaleFactor scale_factor) const override;
+  bool UsingSystemTheme() const override;
+  gfx::ImageSkia* GetImageSkiaNamed(int id) const override;
+  SkColor GetColor(int id) const override;
+  int GetDisplayProperty(int id) const override;
+  bool ShouldUseNativeFrame() const override;
+  bool HasCustomImage(int id) const override;
+  base::RefCountedMemory* GetRawData(int id, ui::ScaleFactor scale_factor)
+      const override;
 #if defined(OS_MACOSX)
-  virtual NSImage* GetNSImageNamed(int id) const override;
-  virtual NSColor* GetNSImageColorNamed(int id) const override;
-  virtual NSColor* GetNSColor(int id) const override;
-  virtual NSColor* GetNSColorTint(int id) const override;
-  virtual NSGradient* GetNSGradient(int id) const override;
+  NSImage* GetNSImageNamed(int id) const override;
+  NSColor* GetNSImageColorNamed(int id) const override;
+  NSColor* GetNSColor(int id) const override;
+  NSColor* GetNSColorTint(int id) const override;
+  NSGradient* GetNSGradient(int id) const override;
 #endif
 
   // Overridden from content::NotificationObserver:
-  virtual void Observe(int type,
-                       const content::NotificationSource& source,
-                       const content::NotificationDetails& details) override;
+  void Observe(int type,
+               const content::NotificationSource& source,
+               const content::NotificationDetails& details) override;
 
   // Set the current theme to the theme defined in |extension|.
   // |extension| must already be added to this profile's