Fix bug which causes proxy authentication requests to crash Debug builds.
Fix bug which causes proxy authentication requests
to crash Debug builds.

BUG=39329
TEST=Mocking a proxy isn't trivial. Ideas?
Review URL: http://codereview.chromium.org/1355001

git-svn-id: http://src.chromium.org/svn/trunk/src@43483 4ff67af0-8c30-449e-8e8b-ad334ec8d88c

Former-commit-id: ead2a43fc91a72df9cce5497d78c42e351053ce7
meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser