More accurate implementation of watched thread time for Gpu Watchdog.
This change leverages an accurate implementation of ThreadTicks to
allow GPU Watchdog thread report watched thread specific CPU time
deltas to help with GPU hang crash dump analysis.
This includes a small refactoring of ThreadTicks class that adds an
overload of ThreadTicks::Now that accepts an arbitrary thread handle
as an argument. That is limited to Windows OS only but if necessary we
could extend it to other platforms.