This updates viewer to show the full frametime including getting new buffers
and presenting buffers to the screen. This is more useful information than
simply the sum the flush and paint.
In a follow up CL we'll enable disabling vsync so we can truly measure how
long it takes us to draw.
Bug: skia:
Change-Id: Ibdbf16b37b44309fca6e771272ce38fd31a0e95c
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/202708
Reviewed-by: Brian Osman <brianosman@google.com>
Commit-Queue: Greg Daniel <egdaniel@google.com>
655002b8b0