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/extensions/extension_system.cc

@@ -261,6 +261,13 @@ scoped_ptr<ExtensionSet> CefExtensionSystem::GetDependentExtensions(
   return make_scoped_ptr(new ExtensionSet());
 }
 
+void CefExtensionSystem::InstallUpdate(const std::string& extension_id,
+                                       const base::FilePath& temp_dir) {
+  NOTREACHED();
+  base::DeleteFile(temp_dir, true /* recursive */);
+}
+
+
 CefExtensionSystem::ComponentExtensionInfo::ComponentExtensionInfo(
     const base::DictionaryValue* manifest, const base::FilePath& directory)
     : manifest(manifest),