Move WebDialogWebContentsDelegate to ui/web_dialogs.

ui/web_dialogs/web_dialogs.gyp

 # 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': {
     'chromium_code': 1,
   },
   'targets': [
     {
@@ skipping 10 matching lines @@
       ],
       'sources': [
         # All .cc, .h under web_dialogs, except unittests.
         'constrained_web_dialog_ui.cc',
         'constrained_web_dialog_ui.h',
         'web_dialog_delegate.cc',
         'web_dialog_delegate.h',
         'web_dialog_observer.h',
         'web_dialog_ui.cc',
         'web_dialog_ui.h',
+        'web_dialog_web_contents_delegate.cc',
+        'web_dialog_web_contents_delegate.h',
         'web_dialogs_export.h',
       ],
     },
   ],
 }