Remove OneClickSigninHelper since it is no longer used.

chrome/chrome_browser_ui.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': {
     # There are two sections of sources:
     # * "Platform"-based sources (OS, toolkit, etc.)
     # * Feature/directory-based sources (e.g., history, printing)
 
@@ skipping 2564 matching lines @@
     'chrome_browser_ui_one_click_signin_sources': [
       'browser/ui/cocoa/one_click_signin_bubble_controller.h',
       'browser/ui/cocoa/one_click_signin_bubble_controller.mm',
       'browser/ui/cocoa/one_click_signin_dialog_controller.h',
       'browser/ui/cocoa/one_click_signin_dialog_controller.mm',
       'browser/ui/cocoa/one_click_signin_view_controller.h',
       'browser/ui/cocoa/one_click_signin_view_controller.mm',
       'browser/ui/sync/one_click_signin_bubble_delegate.h',
       'browser/ui/sync/one_click_signin_bubble_links_delegate.cc',
       'browser/ui/sync/one_click_signin_bubble_links_delegate.h',
-      'browser/ui/sync/one_click_signin_helper.cc',
-      'browser/ui/sync/one_click_signin_helper.h',
       'browser/ui/sync/one_click_signin_sync_observer.cc',
       'browser/ui/sync/one_click_signin_sync_observer.h',
       'browser/ui/sync/one_click_signin_sync_starter.cc',
       'browser/ui/sync/one_click_signin_sync_starter.h',
       'browser/ui/views/sync/one_click_signin_bubble_view.cc',
       'browser/ui/views/sync/one_click_signin_bubble_view.h',
     ],
     'chrome_browser_ui_plugin_sources': [
       'browser/ui/hung_plugin_tab_helper.cc',
       'browser/ui/hung_plugin_tab_helper.h',
@@ skipping 532 matching lines @@
           ],
           'sources': [
             '<@(chrome_browser_ui_non_mobile_sources)',
             '<@(chrome_browser_ui_omnibox_non_mobile_sources)',
           ],
         }],
       ],
     },
   ],
 }