GitLab

I'd like to add this for handling several features of Google Drive API
that is only available for whitelisted first-party client.
By checking the key by the newly added function, we can provide
better fallbacks for clients with third-party keys, instead of just failing.

BUG=332332, 324166

Review URL: https://codereview.chromium.org/131743018

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@245504 0039d316-1c4b-4281-b951-d872f2087c98