Force databases and localstorage to be enabled extensions.

chrome/test/data/extensions/api_test/storage/tab.html

+<script src="api_test.js"></script>
+<script>
+  // Check that the localstorage stuff we stored is still there.
+  expectTrue(localStorage.foo == "bar");
+
+  // Check that the database stuff we stored is still there.
+  var db = window.openDatabase("mydb2", "1.0", "database test", 2048);
+  db.transaction(function(tx) {
+    tx.executeSql("select body from note", [], function(tx, results) {
+      expectTrue(results.rows.length == 1);
+      expectTrue(results.rows.item(0).body == "hotdog");
+      allTestsSucceeded();
+    });
+  }, function(error) {
+    fail(error.message);
+  });
+</script>