Adds an updated safety check for DOM UI renderers.

      We should not be passing web URLs to DOM UI renderers. This CL
adds a check to ensure that we only navigate to DOM-UI-permitted
URLs in such renderers. 

BUG=40575, 40893
TEST=none 

Review URL: http://codereview.chromium.org/1631009

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@44112 0039d316-1c4b-4281-b951-d872f2087c98