Primarily fix the width/height of the drawing surface,
but also pull in changes from July 2020 update.

TBR: courtneygo@google.com,jmadill@chromium.org

Test: angle_perftests --gtest_filter="*Trace*"
Bug: b/157672184
Change-Id: Ia6e16f6d695954f50b3d2a4e8aaaa88514b461d1
Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/2343453Reviewed-by: Cody Northrop <cnorthrop@google.com>
Commit-Queue: Cody Northrop <cnorthrop@google.com>