Update Mojo platform handle wrapping APIs

Updates platform handle wrapping/unwrapping API signatures to be more
extensible for a stable ABI, and adds support to shared memory region
wrapping/unwrapping for writable regions, which may be represented by
multiple platform handles on some platforms.

TBR=bajones@chromium.org

Bug: 826213,842037
Change-Id: Ia0e5da7b7e0f4c41853eb3a8d4a12da47071dd8c
Reviewed-on: https://chromium-review.googlesource.com/1058440
Reviewed-by: Daniel Cheng <dcheng@chromium.org>
Reviewed-by: Jay Civelli <jcivelli@chromium.org>
Reviewed-by: Ken Rockot <rockot@chromium.org>
Commit-Queue: Ken Rockot <rockot@chromium.org>
Cr-Commit-Position: refs/heads/master@{#559165}

CrOS-Libchrome-Original-Commit: 88be045ef0409b129a50955fb89d69c616e31ca2
14 files changed
tree: 5204eddf999a6e241c2d6ff6c2267cdc1f127465
  1. base/
  2. build/
  3. components/
  4. dbus/
  5. device/
  6. ipc/
  7. mojo/
  8. testing/
  9. third_party/
  10. ui/