Add missing performance.js to MANIFEST
Add missing performance.js to MANIFEST

This is for the trunk. The previous CL was for the
release branch.

Review URL: http://codereview.chromium.org/170009

git-svn-id: http://src.chromium.org/svn/trunk/src@23477 4ff67af0-8c30-449e-8e8b-ad334ec8d88c

Former-commit-id: 18bb5f5f42c4c9593787dad29106b502574fc1ba
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