Create c/b/ui/cocoa/test and move test files to there

chrome/browser/ui/cocoa/menu_button_unittest.mm

 // Copyright (c) 2012 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 "base/mac/scoped_nsobject.h"
 #import "chrome/browser/ui/cocoa/clickhold_button_cell.h"
-#import "chrome/browser/ui/cocoa/cocoa_test_helper.h"
 #import "chrome/browser/ui/cocoa/menu_button.h"
+#import "chrome/browser/ui/cocoa/test/cocoa_test_helper.h"
 
 @interface MenuButtonTestDelegate : NSObject<NSMenuDelegate> {
  @private
   base::scoped_nsobject<NSMenu> menu_;
   BOOL open_;
   BOOL didOpen_;
 }
 - (BOOL)isOpen;
 - (BOOL)didOpen;
 @end
@@ skipping 262 matching lines @@
   // click are turned on.
   actionNames = [buttonCell accessibilityActionNames];
   EXPECT_TRUE([actionNames containsObject:NSAccessibilityShowMenuAction]);
 
   [buttonCell accessibilityPerformAction:NSAccessibilityShowMenuAction];
   EXPECT_TRUE([delegate didOpen]);
   EXPECT_FALSE([delegate isOpen]);
 }
 
 }  // namespace