Implement smoother autosizing of the extension options overlay

chrome/browser/guest_view/extension_options/extension_options_constants.cc

 // 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.
 
 #include "chrome/browser/guest_view/extension_options/extension_options_constants.h"
 
 namespace extensionoptions {
 
 // API namespace.
 extern const char kAPINamespace[] = "extensionOptionsInternal";
 
 // Attributes.
 const char kAttributeAutoSize[] = "autosize";
 const char kAttributeMaxHeight[] = "maxheight";
 const char kAttributeMaxWidth[] = "maxwidth";
 const char kAttributeMinHeight[] = "minheight";
 const char kAttributeMinWidth[] = "minwidth";
 
 const char kExtensionId[] = "extensionId";
-const char kHeight[] = "height";
-const char kWidth[] = "width";
+
+const char kNewHeight[] = "newHeight";
+const char kNewWidth[] = "newWidth";
+const char kOldHeight[] = "oldHeight";
+const char kOldWidth[] = "oldWidth";
+
 
 }  // namespace extensionoptions