Add a couple CHECK()s in hopes of helping to track down a crash.

BUG=13500
TEST=none
Review URL: http://codereview.chromium.org/118453

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@18128 0039d316-1c4b-4281-b951-d872f2087c98
1 file changed