Make the cube spin in the JS mojo app.

R=abarth@chromium.org

Review URL: https://codereview.chromium.org/126743002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@243637 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 243637