Update documentation for heap profiler.

Change-Id: Icf63c40bfeb356bb219a9ba0f8fd215030bc45f0
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1531229
Reviewed-by: enne <enne@chromium.org>
Commit-Queue: Erik Chen <erikchen@chromium.org>
Cr-Commit-Position: refs/heads/master@{#642244}
1 file changed