Add a new GetInstance() method for remaining files with singleton classes under chrome/browser.

chrome/browser/ui/cocoa/accelerators_cocoa_unittest.mm

 // Copyright (c) 2010 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.
 
 #import <Cocoa/Cocoa.h>
 
 #include "app/menus/accelerator_cocoa.h"
 #include "base/singleton.h"
 #include "chrome/app/chrome_command_ids.h"
 #import "chrome/browser/ui/cocoa/accelerators_cocoa.h"
 #include "testing/gtest/include/gtest/gtest.h"
 #include "testing/gtest_mac.h"
 
 TEST(AcceleratorsCocoaTest, GetAccelerator) {
-  AcceleratorsCocoa* keymap = Singleton<AcceleratorsCocoa>::get();
+  AcceleratorsCocoa* keymap = AcceleratorsCocoa::GetInstance();
   const menus::AcceleratorCocoa* accelerator =
       keymap->GetAcceleratorForCommand(IDC_COPY);
   ASSERT_TRUE(accelerator);
   EXPECT_NSEQ(@"c", accelerator->characters());
   EXPECT_EQ(static_cast<int>(NSCommandKeyMask), accelerator->modifiers());
 }
 
 TEST(AcceleratorsCocoaTest, GetNullAccelerator) {
-  AcceleratorsCocoa* keymap = Singleton<AcceleratorsCocoa>::get();
+  AcceleratorsCocoa* keymap = AcceleratorsCocoa::GetInstance();
   const menus::AcceleratorCocoa* accelerator =
       keymap->GetAcceleratorForCommand(314159265);
   EXPECT_FALSE(accelerator);
 }