Implement smoother autosizing of the extension options overlay

chrome/renderer/resources/extensions/extension_options_events.js

 // Copyright 2014 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.
 
 var EventBindings = require('event_bindings');
 
 var CreateEvent = function(name) {
   var eventOpts = {supportsListeners: true, supportsFilters: true};
   return new EventBindings.Event(name, undefined, eventOpts);
 };
 
 var EXTENSION_OPTIONS_EVENTS = {
   'close': {
     evt: CreateEvent('extensionOptionsInternal.onClose'),
     fields: []
   },
   'load': {
     evt: CreateEvent('extensionOptionsInternal.onLoad'),
     fields: []
   },
   'sizechanged': {
     evt: CreateEvent('extensionOptionsInternal.onSizeChanged'),
-    customHandler: function(handler, event, webViewEvent) {
-      handler.handleSizeChangedEvent(event, webViewEvent);
+    customHandler: function(handler, event, extensionOptionsEvent) {
+      handler.handleSizeChangedEvent(event, extensionOptionsEvent);
     },
-    fields:['width', 'height']
+    fields:['newWidth', 'newHeight', 'oldWidth', 'oldHeight']
   }
 }
 
 /**
  * @constructor
  */
 function ExtensionOptionsEvents(extensionOptionsInternal, viewInstanceId) {
   this.extensionOptionsInternal = extensionOptionsInternal;
   this.viewInstanceId = viewInstanceId;
   this.setup();
@@ skipping 23 matching lines @@
       return;
     }
     self.extensionOptionsInternal.dispatchEvent(extensionOptionsEvent);
   }, {instanceId: self.viewInstanceId});
 
   this.extensionOptionsInternal.setupEventProperty(name);
 };
 
 ExtensionOptionsEvents.prototype.handleSizeChangedEvent = function(
     event, extensionOptionsEvent) {
-  this.extensionOptionsInternal.onSizeChanged(extensionOptionsEvent.width,
-                                              extensionOptionsEvent.height);
+  this.extensionOptionsInternal.onSizeChanged(extensionOptionsEvent.newWidth,
+                                              extensionOptionsEvent.newHeight,
+                                              extensionOptionsEvent.oldWidth,
+                                              extensionOptionsEvent.oldHeight);
   this.extensionOptionsInternal.dispatchEvent(extensionOptionsEvent);
 }
 
 exports.ExtensionOptionsEvents = ExtensionOptionsEvents;
 exports.CreateEvent = CreateEvent;