Add the code that finds the right memory information into a shared
location. This will allow it to be reused with other points in the
code.

BUG=angleproject:2167

Change-Id: I72d0522e134666d0a00921cb5ef6bc093473afdf
Reviewed-on: https://chromium-review.googlesource.com/717189
Commit-Queue: Jamie Madill <jmadill@chromium.org>
Reviewed-by: Geoff Lang <geofflang@chromium.org>