* Implement WindowsRealTimeClock::CurrentTimeVal with GetSystemTimeAsFileTime as it supposes to return a POSIX gettimeofday, so that later it can be converted to NTP timee correctly.
* Updated to ClockTest.NtpTime to verify the returned NTP is at least larger than kNtpJan1970.

Current implementation uses timeGetTime, which returns the time since windows is started, which can't be converted to NTP time.

BUG=3325
R=pwestin@webrtc.org

Review URL: https://webrtc-codereview.appspot.com/16509004

git-svn-id: http://webrtc.googlecode.com/svn/trunk@6178 4adac7df-926f-26a2-2b94-8c16560cd09d