Turn on disk I/O access checks for the UI thread on ChromeOS.
Turn on disk I/O access checks for the UI thread on ChromeOS.

BUG=60211
TEST=bots

Review URL: http://codereview.chromium.org/6265024

git-svn-id: http://src.chromium.org/svn/trunk/src@72487 4ff67af0-8c30-449e-8e8b-ad334ec8d88c

Former-commit-id: 7ad0af0fc9c13587911c44f651f649e657e89186
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