Cherry-pick: [Android WebView] Only throttle fallback tick

Cherry-pick of Chromium

BUG: 11230312

Original description:

When throttling, either when paused or when in background, only throttle
fallback tick. There are apps relying on the fact that invalidates are
not throttled when paused. When in background, framework should take
care of not calling back with draw for invalidates.

Change-Id: I4e7a4baed8de015d3cb0c18ecaf30b655784923b
1 file changed