If currentExtent is unspecified and EGL_WIDTH & EGL_HEIGHT are provided,
we'll use a surface size of 0xFFFFFFFF. That's not going to work and
appears to be a typo. Use the size specified in EGL_WIDTH & EGL_HEIGHT
instead.

BUG=angleproject:2475
TEST=angle_end2end_tests on Fuchsia with an earlier version of
  CL 1446496 PS12. It is N/A with later patches.

Change-Id: I7e67b2c796318bed512dd6d5d22ef2183916416d
Reviewed-on: https://chromium-review.googlesource.com/c/1461637
Commit-Queue: Michael Spang <spang@chromium.org>
Reviewed-by: Jamie Madill <jmadill@chromium.org>