Adds support for input event latency reporting for Mus.
There's two subtle differences between the Mus flow and the non-Mus flow:
- DISPLAY_COMPOSITOR_RECEIVED_FRAME_COMPONENT is logged if there are ANY latency
  components present.
- OnGpuSwapBuffersCompleted() is called if there are ANY latency components
  present.
In non-Mus flow these are done only when there are browser-specific latency
components present. In practice this shouldn't have any effect on UMA latency
reporting, because currently OnGpuSwapBuffersCompleted() exits early if it doesn't
see RWH-specific latency components. However it should prove useful for getting
latency data for non-blink use cases in the future.

Other changes:
- Adds logging of DISPLAY_COMPOSITOR_RECEIVED_FRAME_COMPONENT in
  SurfaceFactory::SubmitCompositorFrame().
- Plumbs through LatencyInfo propagation for the in-process GPU
  command buffer case (i.e. for Mus GPU).
- Adds LatencyTracker to DisplayOutputSurface...