Fix Drive API JSON data parsing in OnGetDocument().

OnGetDocument, we have to parse data using Drive API's parser
rather than WAPI's parser.

Usage of Drive API is disabled by default, no test to
verify this at this moment.

BUG=152230
TEST=none

Review URL: https://codereview.chromium.org/11233031

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@165300 0039d316-1c4b-4281-b951-d872f2087c98
1 file changed