Element access to the chrome.storage API and localStorage APIs. Selects which one to use based on whether or not you're running as a Chrome App. Based on Polymer.dart's core-localstorage-dart, and provides the same API (except I've added the 'sync' attribute to enable Chrome Sync).
Local storage:
<link rel="import" href="../../packages/chrome_storage_dart/chrome_storage_dart.html">
<cross-platform-storage-dart name="key" value="{{ value }}"></cross-platform-storage-dart>
<link rel="import" href="../../packages/chrome_storage_dart/chrome_storage_dart.html">
<cross-platform-storage-dart name="key" value="{{ value }}" sync></cross-platform-storage-dart>
Raw value storage (not stored as JSON):
<link rel="import" href="../../packages/chrome_storage_dart/chrome_storage_dart.html">
<cross-platform-storage-dart name="key" value="{{ value }}" useRaw></cross-platform-storage-dart>
Please file feature requests and bugs at the issue tracker.