If the context is restored within a brief period of time (3 seconds),
recreate members dependent on WebGL state, and fire onRequestRedraw to
the renderer's listeners.
Handle changes to the char atlas better in the demo client.
Tested in Chrome Canary on macOS by running the demo in one window,
and visiting the internal URL about:gpucrash in another window. The
terminal now recovers and redraws properly.
Kenneth Russell
9459553665
