Use simple partial feed fetch on Drive API v2.

By this CL, DriveAPIService starts to use partial feed fetch, so the response
from the server will contain only the declared fields.

BUG=279652
TEST=Ran unit_tests and tested manually.

Review URL: https://chromiumcodereview.appspot.com/24054011

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@224692 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 224692