Refactorings to egl::Surface to enable ref-counting were causing
a situation where we could have two Window surfaces alive at the
same time. This would confuse the window procedure logic in
SurfaceD3D. Releasing the surface fixes this issue and conforms
closely to the wording on the spec on when Surfaces should be
deleted. Also add a test for message loops and surfaces.

BUG=475085
BUG=angleproject:963

Change-Id: Icdee3a7db97c9b54d779dabf1e1f82a89fefc546
Reviewed-on: https://chromium-review.googlesource.com/265064Reviewed-by: Kenneth Russell <kbr@chromium.org>
Tested-by: Jamie Madill <jmadill@chromium.org>