* removes the SwapInterval test. This test was not really based on
   spec language. SwapInterval is highly os-dependent so likely a
   robust test would include some OS-specific logic instead of timing.

 * give the pbuffer surface non-zero dimensions. this fixes an uncaught
   error on Windows and may give better results.

 * lifts a couple Android suppression possibly related to the pbuffer
   bug. a couple tests still fail.

Bug: angleproject:3123
Bug: angleproject:3162
Change-Id: I68e4e943b94d17777704bbe3b8ae7e646fc9c54d
Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/2082131
Commit-Queue: Jamie Madill <jmadill@chromium.org>
Reviewed-by: Yuly Novikov <ynovikov@chromium.org>