Add ScopedObjCClassSwizzler in base/mac, absorbs objc_method_swizzle and ScopedClassSwizzler

ui/base/cocoa/cocoa_base_utils_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 "ui/base/cocoa/cocoa_base_utils.h"
 
 #import <objc/objc-class.h>
 
+#import "base/test/scoped_class_swizzler_mac.h"
 #include "testing/gtest/include/gtest/gtest.h"
 #include "testing/platform_test.h"
 #include "ui/events/event_constants.h"
 #import "ui/events/test/cocoa_test_event_utils.h"
 #import "ui/gfx/test/ui_cocoa_test_helper.h"
 
 // We provide a donor class with a specially modified |modifierFlags|
 // implementation that we swap with NSEvent's. This is because we can't create a
 // NSEvent that represents a middle click with modifiers.
 @interface TestEvent : NSObject
@@ skipping 13 matching lines @@
   // Left Click = same tab.
   NSEvent* me = cocoa_test_event_utils::MouseEventWithType(NSLeftMouseUp, 0);
   EXPECT_EQ(CURRENT_TAB, WindowOpenDispositionFromNSEvent(me));
 
   // Middle Click = new background tab.
   me = cocoa_test_event_utils::MouseEventWithType(NSOtherMouseUp, 0);
   EXPECT_EQ(NEW_BACKGROUND_TAB, WindowOpenDispositionFromNSEvent(me));
 
   // Shift+Middle Click = new foreground tab.
   {
-    ScopedClassSwizzler swizzler([NSEvent class], [TestEvent class],
-                                 @selector(modifierFlags));
+    base::ScopedClassSwizzler swizzler([NSEvent class], [TestEvent class],
+                                       @selector(modifierFlags));
     me = cocoa_test_event_utils::MouseEventWithType(NSOtherMouseUp,
                                                     NSShiftKeyMask);
     EXPECT_EQ(NEW_FOREGROUND_TAB, WindowOpenDispositionFromNSEvent(me));
   }
 
   // Cmd+Left Click = new background tab.
   me = cocoa_test_event_utils::MouseEventWithType(NSLeftMouseUp,
                                                   NSCommandKeyMask);
   EXPECT_EQ(NEW_BACKGROUND_TAB, WindowOpenDispositionFromNSEvent(me));
 
   // Cmd+Shift+Left Click = new foreground tab.
   me = cocoa_test_event_utils::MouseEventWithType(NSLeftMouseUp,
                                               NSCommandKeyMask |
                                               NSShiftKeyMask);
   EXPECT_EQ(NEW_FOREGROUND_TAB, WindowOpenDispositionFromNSEvent(me));
 
   // Shift+Left Click = new window
   me = cocoa_test_event_utils::MouseEventWithType(NSLeftMouseUp,
                                                   NSShiftKeyMask);
   EXPECT_EQ(NEW_WINDOW, WindowOpenDispositionFromNSEvent(me));
 }
 
 }  // namespace
 
 }  // namespace ui