Coverity: Pass strings by reference.
Coverity: Pass strings by reference.

CID=4139
BUG=none
TEST=none
Review URL: http://codereview.chromium.org/159352

git-svn-id: http://src.chromium.org/svn/trunk/src@21699 4ff67af0-8c30-449e-8e8b-ad334ec8d88c

Former-commit-id: 2f9f7a112e42980bb15af9b76e83efd448291ba5
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