MailboxManagerSync: don't try to share textures with images

We can't bind 2 GLImage to the same textures, and it wouldn't work anyway.
Ensure we don't attempt to create an EGLImage in that case as it will break if
e.g. the image is in UNBOUND state.

Bug: 882513
Change-Id: Iea52d25771a43205a6250b0d354593af98676a86
Reviewed-on: https://chromium-review.googlesource.com/c/1330765
Reviewed-by: Jonathan Backer <backer@chromium.org>
Commit-Queue: Antoine Labour <piman@chromium.org>
Cr-Commit-Position: refs/heads/master@{#607304}
2 files changed