Fix TileResourceFreedIfLostWhileExported

After switching one-copy to SharedImageInterface,
TileResourceFreedIfLostWhileExported lost its meaning as it's only
counting staging textures instead of resource textures. This restores
the behavior by making sure we ask the SharedImageInterface on the
worker context (where they are created now) instead of the
GLES2Interface on the compositor context.

Bug: 882513
Change-Id: I1257c9e130bfa615d56602b0ce74f2830d5a55f5
Reviewed-on: https://chromium-review.googlesource.com/c/1325087
Commit-Queue: Antoine Labour <piman@chromium.org>
Reviewed-by: Jonathan Backer <backer@chromium.org>
Cr-Commit-Position: refs/heads/master@{#606614}
3 files changed