Move some extensions renderer resources to extensions_renderer_resources.grd.

extensions/renderer/resources/unload_event.js

 // Copyright 2013 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.
 
 // Special unload event. We don't use the DOM unload because that slows down
 // tab shutdown. On the other hand, onUnload might not always fire, since
 // Chrome will terminate renderers on shutdown (SuddenTermination).
 
 // Implement a primitive subset of the Event interface as needed, since if this
 // was to use the real event object there would be a circular dependency.
@@ skipping 13 matching lines @@
 };
 
 exports.wasDispatched = false;
 
 // dispatch() is called from C++.
 exports.dispatch = function() {
   exports.wasDispatched = true;
   for (var i = 0; i < listeners.length; ++i)
     listeners[i]();
 };