Update to Chromium revision 304f01a1 (#358063)

- Improve ordering of CefLoadHandler callbacks. OnLoadingStateChange will
  be called before and after all calls to OnLoadStart and OnLoadEnd.
  OnLoadStart/OnLoadEnd calls will occur as matching pairs
  (see http://crbug.com/539952#c2).
- Remove the |requesting_url| argument to CefGeolocationHandler::
  OnCancelGeolocationPermission. Clients can use the |request_id| argument
  to track this information themselves.
- Fix a crash when loading the PDF extension in multiple browsers with a
  custom CefRequestContext (issue #1757).

patch/patches/browser_frame_host_guest_1687.patch

@@ -1,5 +1,5 @@
 diff --git render_widget_host_view_guest.cc render_widget_host_view_guest.cc
-index ecda893d..446c6e6 100644
+index b389e40..c3b5d3e 100644
 --- render_widget_host_view_guest.cc
 +++ render_widget_host_view_guest.cc
 @@ -191,6 +191,9 @@ void RenderWidgetHostViewGuest::Destroy() {