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).

libcef/browser/context.cc

@@ -37,7 +37,7 @@
 #include "ui/base/ui_base_switches.h"
 
 #if defined(OS_WIN)
-#include "content/public/app/startup_helper_win.h"
+#include "content/public/app/sandbox_helper_win.h"
 #include "sandbox/win/src/sandbox_types.h"
 #endif
 
@@ -195,7 +195,7 @@ void CefQuitMessageLoop() {
     return;
   }
 
-  CefBrowserMessageLoop::current()->Quit();
+  CefBrowserMessageLoop::current()->QuitWhenIdle();
 }
 
 void CefSetOSModalLoop(bool osModalLoop) {