Web Inspector: [Resources] Local Storage: duplicate keys are processed inappropriately.
https://bugs.webkit.org/show_bug.cgi?id=112402

Reviewed by Alexander Pavlov.

When user creates new items or renames existing one some existing item
may be overriden. If value is changed, then frontend will receive
notification and update record appropriately.

If item value hasn't been changed, then no notification comes.
But UI still expect / rely on this notification.

With this patch the "no notification" scenario is fixed:
duplicate items are removed.

Another scenario is when update notification comes when we started
editing value (after entering / renaming key). In this case
selected node should not be changed to leave user in editing mode.

* inspector/front-end/DOMStorageItemsView.js:
Added workarounds for "no notification" and "useless notification".


git-svn-id: http://svn.webkit.org/repository/webkit/trunk@146057 268f45cc-cd09-0410-ab3c-d52691b4dbfc