Remove remaining WebContentsImpl from InterstitialPageImpl.

content/content_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.
 
 {
   'dependencies': [
     'browser/speech/proto/speech_proto.gyp:speech_proto',
     '../base/base.gyp:base_static',
     '../crypto/crypto.gyp:crypto',
     '../google_apis/google_apis.gyp:google_apis',
@@ skipping 90 matching lines @@
     'public/browser/geolocation_permission_context.h',
     'public/browser/geolocation_provider.h',
     'public/browser/global_request_id.h',
     'public/browser/gpu_data_manager.h',
     'public/browser/gpu_data_manager_observer.h',
     'public/browser/histogram_fetcher.h',
     'public/browser/host_zoom_map.h',
     'public/browser/indexed_db_context.h',
     'public/browser/indexed_db_info.cc',
     'public/browser/indexed_db_info.h',
+    'public/browser/interstitial_page.cc',
     'public/browser/interstitial_page.h',
     'public/browser/invalidate_type.h',
     'public/browser/javascript_dialog_manager.cc',
     'public/browser/javascript_dialog_manager.h',
     'public/browser/load_from_memory_cache_details.cc',
     'public/browser/load_from_memory_cache_details.h',
     'public/browser/load_notification_details.h',
     'public/browser/local_storage_usage_info.cc',
     'public/browser/local_storage_usage_info.h',
     'public/browser/media_device_id.cc',
@@ skipping 1430 matching lines @@
         ['exclude', '^browser/speech/input_tag_speech_dispatcher_host\\.(cc|h)$'],
       ],
     }, {  # input_speech==1
       'dependencies': [
         '../third_party/flac/flac.gyp:libflac',
         '../third_party/speex/speex.gyp:libspeex',
       ],
     }],
   ],
 }