The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/394e5eec470ff9a0d2af4cae796ccd69c86ee783

commit 394e5eec470ff9a0d2af4cae796ccd69c86ee783
Author: ccameron <ccameron@chromium.org>
Date: Thu May 26 01:57:42 2016

Implement GpuMemoryBufferManager::CreateGpuMemoryBufferFromClientId

For buffers created for a child process, open a copy of the buffer in the browser
process before handing the buffer's handle to the child process. When
CreateGpuMemoryBufferFromClientId is called in the browser process, use this
existing copy of the buffer to create a browser-process copy of the buffer.

Update IOSurface implementation to populate the mach port.

BUG= 614791 
CQ_INCLUDE_TRYBOTS=tryserver.chromium.linux:linux_optional_gpu_tests_rel;tryserver.chromium.mac:mac_optional_gpu_tests_rel;tryserver.chromium.win:win_optional_gpu_tests_rel

Review-Url: https://codereview.chromium.org/1993333002
Cr-Commit-Position: refs/heads/master@{#396084}

[modify] https://crrev.com/394e5eec470ff9a0d2af4cae796ccd69c86ee783/content/browser/gpu/browser_gpu_memory_buffer_manager.cc
[modify] https://crrev.com/394e5eec470ff9a0d2af4cae796ccd69c86ee783/content/browser/gpu/browser_gpu_memory_buffer_manager.h
[modify] https://crrev.com/394e5eec470ff9a0d2af4cae796ccd69c86ee783/gpu/ipc/client/gpu_memory_buffer_impl_io_surface.cc

A simpler strategy for this is in
https://codereview.chromium.org/2473973002/

If I find time in the next few days, I may try adding the "open IOSurfaces in the browser" strategy for us to Finch.

This is not being actively investigated at this time. This is not relevant to look at until viz is in place on Mac.