Handle multi-MX-handle file descriptors in Mojo messages on Fuchsia.

Previously the mojo::edk::ChannelFuchsia was hard-wired to cope only
with file-descriptors for simple files, which wrap a single underlying
platform handle, e.g. a virtual memory object containing the file data.

This CL extends the implementation to cope with MXIO file-descriptors
which build on multiple platform resources, notably device files such as
"/dev/zero". We make some assumptions about the contents of the |info|
returned with the unwrapped handles, so this may need revisiting in
future.

Bug: 734791, 740791
Change-Id: I6aac82bb5b34995381d08bd5b0f8df44a156bc37
Reviewed-on: https://chromium-review.googlesource.com/624815
Reviewed-by: Ken Rockot <rockot@chromium.org>
Commit-Queue: Wez <wez@chromium.org>
Cr-Commit-Position: refs/heads/master@{#496479}

CrOS-Libchrome-Original-Commit: da4409217a419c39b18bca164e9467960595a9c5
1 file changed
tree: 177fb1529f14f614b8d9dddb9868258bf266ef99
  1. base/
  2. build/
  3. components/
  4. dbus/
  5. device/
  6. ipc/
  7. mojo/
  8. testing/
  9. third_party/
  10. ui/