localStorage support check borks in packaged Chrome app

[GoogleCodeExporter]

What steps will reproduce the problem?
1. Create a chrome packaged app
2. Try using dat.gui
3. Observe error

What is the expected output? What do you see instead?
Expect that it will work. Instead, an error is thrown because packaged apps 
don't support window.localStorage.
"window.localStorage is not available in packaged apps. Use 
chrome.storage.local instead."

The check for local storage support is failing in this environment. Ideally, it 
will use chrome.storage.local if it is required and available.

    var SUPPORTS_LOCAL_STORAGE = ...


What version of the product are you using? On what operating system?
Used dat.gui.js from build directory in this repo. Chrome latest. MacOSX.

Original issue reported on code.google.com by Josh.Bec...@gmail.com on 18 Jun 2014 at 8:30