heap_find walks all the page of the heap and finds the references to a given
address.

NOTRY=true

Change-Id: I3271ab96d0224acf2361fe5bc4c8b0a608caf091
Reviewed-on: https://chromium-review.googlesource.com/500190
Commit-Queue: Camillo Bruni <cbruni@chromium.org>
Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Cr-Commit-Position: refs/heads/master@{#45202}