Update {virtual,override} to follow C++11 style in components.

components/enhanced_bookmarks/image_store_ios_unittest.mm

 // 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 "components/enhanced_bookmarks/image_store.h"
 
 #import <UIKit/UIKit.h>
 
 #include "base/files/scoped_temp_dir.h"
 #include "base/mac/scoped_cftyperef.h"
@@ skipping 88 matching lines @@
 // Methods to check if persistence is on or not.
 template <class T> bool ShouldPersist();
 template <> bool ShouldPersist<TestImageStore>() { return false; }
 template <> bool ShouldPersist<PersistentImageStore>() { return true; }
 
 // Test fixture class template for the abstract API.
 template <class T>
 class ImageStoreUnitTestIOS : public PlatformTest {
  protected:
   ImageStoreUnitTestIOS() {}
-  virtual ~ImageStoreUnitTestIOS() {}
+  ~ImageStoreUnitTestIOS() override {}
 
-  virtual void SetUp() override {
+  void SetUp() override {
     bool success = temp_dir_.CreateUniqueTempDir();
     ASSERT_TRUE(success);
     store_.reset(CreateStore<T>(temp_dir_));
   }
 
-  virtual void TearDown() override {
+  void TearDown() override {
     if (store_ && use_persistent_store())
       store_->ClearAll();
   }
 
   bool use_persistent_store() const { return ShouldPersist<T>(); }
   void ResetStore() { store_.reset(CreateStore<T>(temp_dir_)); }
 
   // The directory the database is saved into.
   base::ScopedTempDir temp_dir_;
   // The object the fixture is testing, via its base interface.
@@ skipping 23 matching lines @@
     scoped_refptr<enhanced_bookmarks::ImageRecord> image_out =
         this->store_->Get(url);
 
     EXPECT_EQ(image_in->url, image_out->url);
     EXPECT_TRUE(CompareImages(*image_in->image, *image_out->image));
     EXPECT_EQ(image_in->dominant_color, image_out->dominant_color);
   }
 }
 
 }  // namespace