[viewer] Avoid per-frame json UI updates

The reason we push Json updates for every frame is to support the
Android FPS meter - which happens to require the native FPS meter for
updates.

Instead of supporting two meters:

1) scale up the native FPS widget on Android (1.5x)

2) remove the Android widget

3) stop calling updateUIState() from onPaint()

Change-Id: Ica8109869035b2f885743a7e38b50688b69fa5e4
Reviewed-on: https://skia-review.googlesource.com/126621
Reviewed-by: Brian Osman <brianosman@google.com>
Commit-Queue: Florin Malita <fmalita@chromium.org>
7 files changed