[Fuchsia] Add buffer_collection_id in NativePixmapHandle

NativePixmapHandle already contained VMO handle on Fuchsia. VMO handle
can be used to identify buffers, but sysmem returns VMOs only for
buffers for which CPU access was requested and we don't need all
buffers to be CPU accessible. The new fields will allow to identify
sysmem-allocated buffers without relying on VMO handles. VMO handles
are still kept as part of NativePixmapHandle to allow clients access
the buffers.

Bug: 852011
Change-Id: I147af3de9c8f98c6216003ae19702cb67ab0bfcf
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1576167
Commit-Queue: Sergey Ulanov <sergeyu@chromium.org>
Reviewed-by: Michael Spang <spang@chromium.org>
Reviewed-by: Tom Sepez <tsepez@chromium.org>
Cr-Commit-Position: refs/heads/master@{#654136}
6 files changed