[mojo-core] Validate data pipe endpoint metadata

Ensures that we don't blindly trust specified buffer size and offset
metadata when deserializing data pipe consumer and producer handles.

Bug: 877182
Change-Id: I30f3eceafb5cee06284c2714d08357ef911d6fd9
Reviewed-on: https://chromium-review.googlesource.com/1192922
Reviewed-by: Reilly Grant <reillyg@chromium.org>
Commit-Queue: Ken Rockot <rockot@chromium.org>
Cr-Original-Commit-Position: refs/heads/master@{#586704}(cherry picked from commit 66e24a8793615bd9d5c238b1745b093090e1f72d)
Reviewed-on: https://chromium-review.googlesource.com/1195651
Reviewed-by: Krishna Govind <govind@chromium.org>
Cr-Commit-Position: refs/branch-heads/3535@{#7}
Cr-Branched-From: 4d18295073a6bf8f2f4d26e4e059767e091eaaf3-refs/heads/master@{#586474}
2 files changed