[Alarm] Fix failures raised from test suite.

I've downloaded the test suite from http://otcqa.sh.intel.com/qa-auto/live/Web_TCT_Xwalk/ and run them manually.
All the alarm related failures in the test suite have been fixed.

BUG=XWALK-2163
Please reference to here:  http://jsperf.com/number-to-string/2