Move out DidStartProvisionalLoad from WebContentsImpl into Navigator.

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 904 matching lines @@
     'browser/renderer_host/media/web_contents_video_capture_device.cc',
     'browser/renderer_host/media/web_contents_video_capture_device.h',
     'browser/renderer_host/memory_benchmark_message_filter.cc',
     'browser/renderer_host/memory_benchmark_message_filter.h',
     'browser/renderer_host/native_web_keyboard_event.cc',
     'browser/renderer_host/native_web_keyboard_event_android.cc',
     'browser/renderer_host/native_web_keyboard_event_aura.cc',
     'browser/renderer_host/native_web_keyboard_event_gtk.cc',
     'browser/renderer_host/native_web_keyboard_event_mac.mm',
     'browser/renderer_host/native_web_keyboard_event_win.cc',
+    'browser/renderer_host/navigator.cc',
+    'browser/renderer_host/navigator.h',
+    'browser/renderer_host/navigator_observer.h',
     'browser/renderer_host/overscroll_configuration.cc',
     'browser/renderer_host/overscroll_controller.cc',
     'browser/renderer_host/overscroll_controller.h',
     'browser/renderer_host/overscroll_controller_delegate.h',
     'browser/renderer_host/pepper/browser_ppapi_host_impl.cc',
     'browser/renderer_host/pepper/browser_ppapi_host_impl.h',
     'browser/renderer_host/pepper/content_browser_pepper_host_factory.cc',
     'browser/renderer_host/pepper/content_browser_pepper_host_factory.h',
     'browser/renderer_host/pepper/pepper_browser_font_singleton_host.cc',
     'browser/renderer_host/pepper/pepper_browser_font_singleton_host.h',
@@ skipping 623 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',
       ],
     }],
   ],
 }