Fixed bugs to work with 0.5.7+1

BUG=

Review URL: https://chromiumcodereview.appspot.com//14690015
constrain to latest SDK

BUG=

Review URL: https://chromiumcodereview.appspot.com//15101002
work around xtag issue on bleeding_edge

R=alanknight@google.com

Review URL: https://chromiumcodereview.appspot.com//15080008
release 0.4.8+1