Standardize usage of virtual/override/final specifiers in sync/.

sync/internal_api/attachments/attachment_store_handle_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 "sync/internal_api/public/attachments/attachment_store_handle.h"
 
 #include "base/bind.h"
 #include "base/callback.h"
 #include "base/memory/ref_counted.h"
 #include "base/memory/scoped_ptr.h"
@@ skipping 70 matching lines @@
  protected:
   AttachmentStoreHandleTest()
       : init_call_count_(0),
         read_call_count_(0),
         write_call_count_(0),
         drop_call_count_(0),
         read_metadata_call_count_(0),
         read_all_metadata_call_count_(0),
         dtor_call_count_(0) {}
 
-  virtual void SetUp() {
+  void SetUp() override {
     scoped_ptr<AttachmentStoreBase> backend(new MockAttachmentStore(
         base::Bind(&AttachmentStoreHandleTest::InitCalled,
                    base::Unretained(this)),
         base::Bind(&AttachmentStoreHandleTest::ReadCalled,
                    base::Unretained(this)),
         base::Bind(&AttachmentStoreHandleTest::WriteCalled,
                    base::Unretained(this)),
         base::Bind(&AttachmentStoreHandleTest::DropCalled,
                    base::Unretained(this)),
         base::Bind(&AttachmentStoreHandleTest::ReadMetadataCalled,
@@ skipping 94 matching lines @@
 
   // Releasing referehce to AttachmentStoreHandle should result in
   // MockAttachmentStore being deleted on backend loop.
   attachment_store_handle_ = NULL;
   EXPECT_EQ(dtor_call_count_, 0);
   RunMessageLoop();
   EXPECT_EQ(dtor_call_count_, 1);
 }
 
 }  // namespace syncer