Support GrabWindowSnapshot with no g_browser_process

chrome/chrome_browser.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.
 
 {
   'targets': [
     {
       'target_name': 'browser',
       'type': 'static_library',
@@ skipping 4222 matching lines @@
         'browser/ui/webui/web_ui_util.h',
         'browser/ui/window_sizer/window_sizer.cc',
         'browser/ui/window_sizer/window_sizer.h',
         'browser/ui/window_sizer/window_sizer_ash.cc',
         'browser/ui/window_sizer/window_sizer_aura.cc',
         'browser/ui/window_sizer/window_sizer_gtk.cc',
         'browser/ui/window_sizer/window_sizer_mac.mm',
         'browser/ui/window_sizer/window_sizer_win.cc',
         'browser/ui/window_snapshot/window_snapshot.cc',
         'browser/ui/window_snapshot/window_snapshot.h',
-        'browser/ui/window_snapshot/window_snapshot_aura.cc',
-        'browser/ui/window_snapshot/window_snapshot_gtk.cc',
-        'browser/ui/window_snapshot/window_snapshot_mac.mm',
-        'browser/ui/window_snapshot/window_snapshot_win.cc',
         'browser/ui/zoom/zoom_controller.cc',
         'browser/ui/zoom/zoom_controller.h',
         'browser/ui/zoom/zoom_observer.h',
         'browser/upgrade_detector.cc',
         'browser/upgrade_detector.h',
         'browser/upgrade_detector_impl.cc',
         'browser/upgrade_detector_impl.h',
         'browser/usb/usb_device.cc',
         'browser/usb/usb_device.h',
         'browser/usb/usb_service.cc',
@@ skipping 1229 matching lines @@
           'variables': {
             'jni_gen_dir': 'chrome',
           },
           'includes': [ '../build/jni_generator.gypi' ],
         },
       ],
      },
     ],
   ],
 }