Add the ability to trigger synced notifications in the Sync test server.

This CL also adds the option of changing the ClientCommand sent back to
the client in order to modify the commit delay for sessions. After this
change is submitted, a frontend will be added to allow easy triggering
of canned notifications.

Review URL: https://codereview.chromium.org/70933002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@236619 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 236619
Remove bookmark api helper function overloads.

Converts the one remaining use of these functions to use the JSON
schema compiler generated classes instead.

BUG=

Review URL: https://codereview.chromium.org/79953003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@236620 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 236620