After http://crbug.com/17325 in case of unaccessible iframe.contentDocument because of security reasons SecurityError exception is sent. Previously there were no exception, but contentDocument was undefined.

Add support for SecurityError exception to dialogs.js .

BUG=306608
TEST=manual

Review URL: https://codereview.chromium.org/27222002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@228673 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 228673