metrics: don't record metrics unless user has opted-in.
metrics: don't record metrics unless user has opted-in.

This worked before, but regressed for Chromium builds.

BUG=2278

Review URL: http://codereview.chromium.org/113350

git-svn-id: http://src.chromium.org/svn/trunk/src@15985 4ff67af0-8c30-449e-8e8b-ad334ec8d88c

Former-commit-id: 4d85e5d9905c289af1d44d3b63442a923917e28e
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