GitLab

This function returns an object whose keys are the notification
IDs of all notifications created by that extension.

BUG=240924

TBR=miket@chromium.org

Review URL: https://chromiumcodereview.appspot.com/15715008

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@203001 0039d316-1c4b-4281-b951-d872f2087c98