Fix gcc warning in chrome os compile.
Fix gcc warning in chrome os compile.

TBR=jungshik

Review URL: http://codereview.chromium.org/242001

git-svn-id: http://src.chromium.org/svn/trunk/src@27167 4ff67af0-8c30-449e-8e8b-ad334ec8d88c

Former-commit-id: 494e89c74ff1e22f06c3e8fe1973221161eee27c
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