SkTime::GetNSecs()

   - Move high-precision wall timers from tools/timer to SkTime.
   - Implement SkTime::GetMSecs() in terms of SkTime::GetNSecs().
   - Delete unused tools/timer code.

I have no idea what's going on there in src/animator.
I don't intend to investigate.

BUG=skia:

Committed: https://skia.googlesource.com/skia/+/70084cbc16ee8162649f2601377feb6e49de0217

CQ_EXTRA_TRYBOTS=client.skia.compile:Build-Ubuntu-GCC-x86_64-Debug-CrOS_Link-Trybot

Review URL: https://codereview.chromium.org/1422513003
19 files changed