GitLab

This CL implements step 2 in the refactoring described by
http://crbug.com/951391, which attemps to port the viz
component and service to use our new shared memory API
(base::SharedMemory is deprecated).

It modifies SharedBitmapManager::ChildAddedSharedBitmap
to accept WritableSharedMemoryMapping values directly.

This simplifies the implementation and gets rid of
Mojo handle usage to pass shared memory region, in
favor of the new base::UnsafeSharedMemoryRegion and
base::WritableSharedMemoryMapping types.

BUG=951391,795291
R=alexilin@chromium.org, enne@chromium.org, danakj@chromium.org, piman@chromium.org, samans@chromium.org, liberato@chromium.org

Change-Id: I0314f43f64fc4cd5591c65816b764adb97fe6b13
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1571648
Commit-Queue: David Turner <digit@chromium.org>
Reviewed-by: Saman Sami <samans@chromium.org>
Cr-Commit-Position: refs/heads/master@{#658520}