[Mac] Add testing code to expose an NSColor memory leak.

chrome/chrome.gyp

 # Copyright (c) 2009 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.
 
 {
   'variables': {
     'chromium_code': 1,
 
     # Define the common dependencies that contain all the actual
     # Chromium functionality.  This list gets pulled in below by
@@ skipping 891 matching lines @@
         'browser/cocoa/browser_window.mm',
         'browser/cocoa/browser_window_cocoa.h',
         'browser/cocoa/browser_window_cocoa.mm',
         'browser/cocoa/browser_window_controller.h',
         'browser/cocoa/browser_window_controller.mm',
         'browser/cocoa/clear_browsing_data_controller.h',
         'browser/cocoa/clear_browsing_data_controller.mm',
         'browser/cocoa/clickhold_button_cell.h',
         'browser/cocoa/clickhold_button_cell.mm',
         'browser/cocoa/cocoa_test_helper.h',
+        'browser/cocoa/cocoa_test_helper.mm',
         'browser/cocoa/command_observer_bridge.h',
         'browser/cocoa/command_observer_bridge.mm',
         'browser/cocoa/constrained_window_mac.h',
         'browser/cocoa/constrained_window_mac.mm',
         'browser/cocoa/custom_home_pages_model.h',
         'browser/cocoa/custom_home_pages_model.mm',
         'browser/cocoa/delayedmenu_button.h',
         'browser/cocoa/delayedmenu_button.mm',
         'browser/cocoa/download_item_cell.h',
         'browser/cocoa/download_item_cell.mm',
@@ skipping 4919 matching lines @@
               # Use outputs of this action as inputs for the main target build.
               # Seems as a misnomer but makes this happy on Linux (scons).
               'process_outputs_as_sources': 1,
             },
           ],  # 'actions'
         },
       ]
     }],
   ],  # 'conditions'
 }