DevTools: remove default thick borders from the dialogs.

Review URL: https://codereview.chromium.org/437443003

git-svn-id: svn://svn.chromium.org/blink/trunk@179325 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Add a UseCounter for the composite attribute on <img>

This was added for Apple's Dashboard in 2004:
http://trac.webkit.org/changeset/6491

Hopefully it's not used on the Web and can be removed.

Remove the FIXME as it certainly shouldn't be expanded.

Review URL: https://codereview.chromium.org/438623002

git-svn-id: svn://svn.chromium.org/blink/trunk@179326 bbb929c8-8fbe-4397-9dbb-9b2b20218538