Standardize usage of virtual/override/final in mojo/

mojo/services/native_viewport/platform_viewport_mac.mm

 // Copyright 2013 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 "mojo/services/native_viewport/platform_viewport.h"
 
 #import <AppKit/NSApplication.h>
 #import <AppKit/NSView.h>
 #import <AppKit/NSWindow.h>
 
 #include "base/bind.h"
 #include "ui/gfx/rect.h"
 
 namespace mojo {
 
 class PlatformViewportMac : public PlatformViewport {
  public:
   PlatformViewportMac(Delegate* delegate)
       : delegate_(delegate),
         window_(nil) {
   }
 
-  virtual ~PlatformViewportMac() {
+  ~PlatformViewportMac() override {
     [window_ orderOut:nil];
     [window_ close];
   }
 
  private:
   // Overridden from PlatformViewport:
-  virtual void Init(const gfx::Rect& bounds) override {
+  void Init(const gfx::Rect& bounds) override {
     [NSApplication sharedApplication];
 
     rect_ = bounds;
     window_ = [[NSWindow alloc]
                   initWithContentRect:NSRectFromCGRect(rect_.ToCGRect())
                             styleMask:NSTitledWindowMask
                               backing:NSBackingStoreBuffered
                                 defer:NO];
     delegate_->OnAcceleratedWidgetAvailable([window_ contentView]);
     delegate_->OnBoundsChanged(rect_);
   }
 
-  virtual void Show() override {
-    [window_ orderFront:nil];
-  }
+  void Show() override { [window_ orderFront:nil]; }
 
-  virtual void Hide() override {
-    [window_ orderOut:nil];
-  }
+  void Hide() override { [window_ orderOut:nil]; }
 
-  virtual void Close() override {
+  void Close() override {
     // TODO(beng): perform this in response to NSWindow destruction.
     delegate_->OnDestroyed();
   }
 
-  virtual gfx::Size GetSize() override {
-    return rect_.size();
-  }
+  gfx::Size GetSize() override { return rect_.size(); }
 
-  virtual void SetBounds(const gfx::Rect& bounds) override {
-    NOTIMPLEMENTED();
-  }
+  void SetBounds(const gfx::Rect& bounds) override { NOTIMPLEMENTED(); }
 
-  virtual void SetCapture() override {
-    NOTIMPLEMENTED();
-  }
+  void SetCapture() override { NOTIMPLEMENTED(); }
 
-  virtual void ReleaseCapture() override {
-    NOTIMPLEMENTED();
-  }
+  void ReleaseCapture() override { NOTIMPLEMENTED(); }
 
   Delegate* delegate_;
   NSWindow* window_;
   gfx::Rect rect_;
 
   DISALLOW_COPY_AND_ASSIGN(PlatformViewportMac);
 };
 
 // static
 scoped_ptr<PlatformViewport> PlatformViewport::Create(Delegate* delegate) {
   return scoped_ptr<PlatformViewport>(new PlatformViewportMac(delegate)).Pass();
 }
 
 }  // namespace mojo