GitLab

Removes TODOs, adds some more important details and an example to the documentation.
Makes the documentation appear on the official developer.chrome.com page.

BUG=364435

Review URL: https://codereview.chromium.org/312503004

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@274591 0039d316-1c4b-4281-b951-d872f2087c98