Add another didRunInsecureContent method.

In order to better log mixed-scripting issues I want to get the URL into
Chrome land. This involves a WebKit change ([1]) but, by making this
change first, we can decouple of the two changes.

[1] https://bugs.webkit.org/show_bug.cgi?id=52384

BUG=none
TEST=compile

http://codereview.chromium.org/6272003/

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@71881 0039d316-1c4b-4281-b951-d872f2087c98