viz: Move more unit tests to components/viz/service/frame_sinks

This CL moves surface_manager_ref_unittest to
components/viz/service/frame_sinks, renaming it to
surface_references_unittest to better capture what it does. This set
of unit tests operate at the Frame Sinks layer because they use
CompositorFrameSinkSupport but then interrogate SurfaceManager to ensure
references are tracked correctly.

This CL also updates includes, forward declarations and namespaces
appropriately.

Bug: 722935
Change-Id: If899a6a1a7a084a4afa077beef4d0bc44a6bc541
Reviewed-on: https://chromium-review.googlesource.com/574883
Reviewed-by: Antoine Labour <piman@chromium.org>
Commit-Queue: Fady Samuel <fsamuel@chromium.org>
Cr-Commit-Position: refs/heads/master@{#487322}
4 files changed