Dynamically calculate the number of extension icons to show per row in overflow

chrome/chrome_tests_unit.gypi

 # Copyright 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': {
     'chrome_unit_tests_sources': [
       '../apps/app_shim/app_shim_host_mac_unittest.cc',
       '../apps/app_shim/extension_app_shim_handler_mac_unittest.cc',
       '../apps/saved_files_service_unittest.cc',
       '../components/autofill/content/renderer/test_password_autofill_agent.cc',
@@ skipping 1190 matching lines @@
       'browser/ui/views/extensions/browser_action_drag_data_unittest.cc',
       'browser/ui/views/extensions/media_galleries_dialog_views_unittest.cc',
       'browser/ui/views/first_run_bubble_unittest.cc',
       'browser/ui/views/frame/browser_view_layout_unittest.cc',
       'browser/ui/views/frame/browser_view_unittest.cc',
       'browser/ui/views/frame/immersive_mode_controller_ash_unittest.cc',
       'browser/ui/views/frame/opaque_browser_frame_view_layout_unittest.cc',
       'browser/ui/views/frame/test_with_browser_view.cc',
       'browser/ui/views/frame/test_with_browser_view.h',
       'browser/ui/views/frame/web_contents_close_handler_unittest.cc',
+      'browser/ui/views/menu_item_view_unittest.cc',
       'browser/ui/views/select_file_dialog_extension_unittest.cc',
       'browser/ui/views/status_icons/status_tray_win_unittest.cc',
       'browser/ui/views/sync/one_click_signin_bubble_view_unittest.cc',
       'browser/ui/views/tab_contents/chrome_web_contents_view_delegate_views_unittest.cc',
       'browser/ui/views/tabs/fake_base_tab_strip_controller.cc',
       'browser/ui/views/tabs/fake_base_tab_strip_controller.h',
       'browser/ui/views/tabs/stacked_tab_strip_layout_unittest.cc',
       'browser/ui/views/tabs/tab_strip_unittest.cc',
       'browser/ui/views/tabs/tab_unittest.cc',
       'browser/ui/views/toolbar/reload_button_unittest.cc',
@@ skipping 1651 matching lines @@
               'dependencies': [
                 '../tools/xdisplaycheck/xdisplaycheck.gyp:xdisplaycheck',
               ],
             }],
           ],
         },
       ],
     }],
   ],  # 'conditions'
 }