Add "Instant:" prefix to Instant preview tabs in the Task manager.

chrome/chrome_tests.gypi

 # Copyright (c) 2011 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 524 matching lines @@
         'browser/browser_focus_uitest.cc',
         'browser/browser_keyevents_browsertest.cc',
         'browser/collected_cookies_uitest.cc',
         'browser/debugger/devtools_sanity_unittest.cc',
         'browser/infobars/infobars_uitest.cc',
         'browser/instant/instant_browsertest.cc',
         'browser/keyboard_access_uitest.cc',
         'browser/mouseleave_interactive_uitest.cc',
         'browser/notifications/notifications_interactive_uitest.cc',
         'browser/npapi_interactive_test.cc',
+        'browser/task_manager/task_manager_browsertest_util.cc',
         'browser/ui/gtk/bookmarks/bookmark_bar_gtk_interactive_uitest.cc',
         'browser/ui/omnibox/omnibox_view_browsertest.cc',
         'browser/ui/panels/panel_browsertest.cc',
         'browser/ui/views/bookmarks/bookmark_bar_view_test.cc',
         'browser/ui/views/button_dropdown_test.cc',
         'browser/ui/views/constrained_window_views_browsertest.cc',
         'browser/ui/views/find_bar_host_interactive_uitest.cc',
         'browser/ui/views/menu_item_view_test.cc',
         'browser/ui/views/menu_model_adapter_test.cc',
         'browser/ui/views/ssl_client_certificate_selector_browsertest.cc',
@@ skipping 3739 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'
         },
       ]
     }],  # 'coverage!=0'
   ],  # 'conditions'
 }