IndexedDB: Make DOMException messages more useful.

IndexedDB throws a handful of DOMException types for a wide variety of
reasons; IDBObjectStore.put() has 6 cases that throw DataError.

Show web developers a little love by giving specific messages for
each error cases. In most cases the error text is inspired by the
IndexedDB specification itself.

BUG=95723

Review URL: https://chromiumcodereview.appspot.com/18580013

git-svn-id: svn://svn.chromium.org/blink/trunk@154140 bbb929c8-8fbe-4397-9dbb-9b2b20218538