Standardize usage of virtual/override/final specifiers.

extensions/browser/extension_icon_image_unittest.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 "extensions/browser/extension_icon_image.h"
 
 #include <vector>
 
 #include "base/json/json_file_value_serializer.h"
 #include "base/message_loop/message_loop.h"
@@ skipping 107 matching lines @@
                                public IconImage::Observer {
  public:
   ExtensionIconImageTest()
       : image_loaded_count_(0),
         quit_in_image_loaded_(false),
         ui_thread_(BrowserThread::UI, &ui_loop_),
         file_thread_(BrowserThread::FILE),
         io_thread_(BrowserThread::IO),
         notification_service_(content::NotificationService::Create()) {}
 
-  virtual ~ExtensionIconImageTest() {}
+  ~ExtensionIconImageTest() override {}
 
   void WaitForImageLoad() {
     quit_in_image_loaded_ = true;
     base::MessageLoop::current()->Run();
     quit_in_image_loaded_ = false;
   }
 
   int ImageLoadedCount() {
     int result = image_loaded_count_;
     image_loaded_count_ = 0;
@@ skipping 21 matching lines @@
 
     EXPECT_TRUE(valid_value.get());
     if (!valid_value)
       return NULL;
 
     return Extension::Create(test_file, location, *valid_value,
                              Extension::NO_FLAGS, &error);
   }
 
   // testing::Test overrides:
-  virtual void SetUp() override {
+  void SetUp() override {
     file_thread_.Start();
     io_thread_.Start();
   }
 
   // IconImage::Delegate overrides:
   void OnExtensionIconImageChanged(IconImage* image) override {
     image_loaded_count_++;
     if (quit_in_image_loaded_)
       base::MessageLoop::current()->Quit();
   }
@@ skipping 375 matching lines @@
   // image of the size. It could be blank or a rescale from the existing 1.0f
   // icon.
   representation = image_skia.GetRepresentation(2.0f);
 
   EXPECT_EQ(16, representation.GetWidth());
   EXPECT_EQ(16, representation.GetHeight());
   EXPECT_EQ(2.0f, representation.scale());
 }
 
 }  // namespace extensions