Add tests for panel app icon functionaility.

chrome/chrome_tests.gypi

 # 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.
 {
   'variables' : {
     'pyautolib_sources': [
       'app/chrome_command_ids.h',
       'app/chrome_dll_resource.h',
       'common/automation_constants.h',
       'common/pref_names.cc',
@@ skipping 3026 matching lines @@
         'browser/ui/cocoa/web_intent_sheet_controller_browsertest.mm',
         'browser/ui/cocoa/browser_window_controller_browsertest.mm',
         'browser/ui/cocoa/constrained_window/constrained_window_mac_browsertest.mm',
         'browser/ui/find_bar/find_bar_host_browsertest.cc',
         'browser/ui/fullscreen/fullscreen_controller_browsertest.cc',
         'browser/ui/global_error/global_error_service_browsertest.cc',
         'browser/ui/gtk/one_click_signin_bubble_gtk_browsertest.cc',
         'browser/ui/gtk/view_id_util_browsertest.cc',
         'browser/ui/intents/web_intent_picker_controller_browsertest.cc',
         'browser/ui/login/login_prompt_browsertest.cc',
+        'browser/ui/panels/panel_extension_browsertest.cc',
         'browser/ui/prefs/prefs_tab_helper_browsertest.cc',
         'browser/ui/startup/startup_browser_creator_browsertest.cc',
         'browser/ui/tab_modal_confirm_dialog_browsertest.cc',
         'browser/ui/tab_modal_confirm_dialog_browsertest.h',
         'browser/ui/views/ash/browser_non_client_frame_view_ash_browsertest.cc',
         'browser/ui/views/autofill/autofill_external_delegate_views_browsertest.cc',
         'browser/ui/views/browser_actions_container_browsertest.cc',
         'browser/ui/views/constrained_window_views_browsertest.cc',
         'browser/ui/views/frame/app_non_client_frame_view_aura_browsertest.cc',
         'browser/ui/views/frame/browser_view_browsertest.cc',
@@ skipping 1797 matching lines @@
                 '--result', '<@(_outputs)',
                 '--isolate', 'browser_tests.isolate',
               ],
             },
           ],
         },
       ],
     }],
   ],  # 'conditions'
 }