Update from https://crrev.com/315085

This includes the switch to libc++ on Android.

Other fixes:

*) Add (dumb) impl of OrderingBarrier() to command buffer
*) "base/debug/trace_event.h" -> "base/trace_event/trace_event.h"
*) Added a few <cmath> includes to sky

Review URL: https://codereview.chromium.org/903273002