Implement smoother autosizing of the extension options overlay

chrome/renderer/resources/extensions/extension_options_events.js

Index: chrome/renderer/resources/extensions/extension_options_events.js
diff --git a/chrome/renderer/resources/extensions/extension_options_events.js b/chrome/renderer/resources/extensions/extension_options_events.js
index ded82cf0194207ff1d1e72bc0dcf5786bd68d730..1bc517c91c03284d84cabc5ed6daf581e3088575 100644
--- a/chrome/renderer/resources/extensions/extension_options_events.js
+++ b/chrome/renderer/resources/extensions/extension_options_events.js
@@ -20,10 +20,10 @@ var EXTENSION_OPTIONS_EVENTS = {
   },
   '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']
   }
 }
 
@@ -67,8 +67,10 @@ ExtensionOptionsEvents.prototype.setupEvent = function(name, info) {
 
 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);
 }