ppapi: Add SHARED_MEMORY_REGION type to SerializedHandle

This CL adds a new SHARED_MEMORY_REGION type to the SerializedHandle. This new
type is backed up by the base::subtle::PlatformSharedMemoryRegion class that
provides a new recommended API for the shared memory in Chrome.
Eventually, all uses of the SHARED_MEMORY type should be converted to the
SHARED_MEMORY_REGION.

Bug: 845985
Change-Id: Icfb4605dadb6f111efe953d8b940cc879fa40763
Reviewed-on: https://chromium-review.googlesource.com/1076334
Reviewed-by: Ken Rockot <[email protected]>
Reviewed-by: Bill Budge <[email protected]>
Reviewed-by: Daniel Cheng <[email protected]>
Reviewed-by: Derek Schuff <[email protected]>
Commit-Queue: Alexandr Ilin <[email protected]>
Cr-Commit-Position: refs/heads/master@{#563500}
6 files changed