Pointer was freed before using it's contents to set the
value of the ImageExtent to be returned

Bug: 863603
Change-Id: Ibdb26c862f3216e7314516f7aee64942467b4add
Reviewed-on: https://chromium-review.googlesource.com/1137349Reviewed-by: Jamie Madill <jmadill@chromium.org>
Commit-Queue: Jamie Madill <jmadill@chromium.org>