withFrameNanos

Suspends until a new frame is requested, immediately invokes onFrame with the frame time in nanoseconds in the calling context of frame dispatch, then resumes with the result from onFrame.

frameTimeNanos should be used when calculating animation time deltas from frame to frame as it may be normalized to the target time for the frame, not necessarily a direct, "now" value.

The time base of the value provided by withFrameNanos is implementation defined. Time values provided are monotonically increasing; after a call to withFrameNanos completes it must not provide the same value again for a subsequent call.