Throw exceptions when attempts are made to use localStorage in packaged apps.

chrome/renderer/resources/extensions/platform_app.js

Index: chrome/renderer/resources/extensions/platform_app.js
diff --git a/chrome/renderer/resources/extensions/platform_app.js b/chrome/renderer/resources/extensions/platform_app.js
index b9e0f2f9ea909f5fb34ba3023b172c39b735aca9..94154706189f147d7f6449f13df7b55be6f3e437 100644
--- a/chrome/renderer/resources/extensions/platform_app.js
+++ b/chrome/renderer/resources/extensions/platform_app.js
@@ -7,9 +7,11 @@
  *
  * @param {string} messagePrefix text to prepend to the exception message.
  */
-function generateStub(messagePrefix) {
+function generateStub(messagePrefix, opt_messageSuffix) {
   return function() {
-    throw messagePrefix + ' is not available in packaged apps.';
+    var message = messagePrefix + ' is not available in packaged apps.';
+    if (opt_messageSuffix) message = message + ' ' + opt_messageSuffix;
+    throw message;
   };
 }
 
@@ -41,10 +43,11 @@ function stubOutMethods(object, objectName, methodNames) {
  *     to by web developers, e.g. "document" instead of "HTMLDocument").
  * @param {Array.<string>} propertyNames property names
  */
-function stubOutGetters(object, objectName, propertyNames) {
+function stubOutGetters(object, objectName, propertyNames, opt_messageSuffix) {
   propertyNames.forEach(function(propertyName) {
     object.__defineGetter__(
-        propertyName, generateStub(objectName + '.' + propertyName));
+        propertyName, generateStub(
+            objectName + '.' + propertyName, opt_messageSuffix));
   });
 }
 
@@ -75,6 +78,11 @@ stubOutGetters(window, 'window',
     ['locationbar', 'menubar', 'personalbar', 'scrollbars', 'statusbar',
     'toolbar']);
 
+// Disable window.localStorage.
+stubOutGetters(window, 'window',
+    ['localStorage'],
+    'Use chrome.storage.local instead.');
+
 // Disable onunload, onbeforeunload.
 Window.prototype.__defineSetter__(
     'onbeforeunload', generateStub('onbeforeunload'));