The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/0bcca1e6eb7d275c808c26a37f0878e0b66be1d9

commit 0bcca1e6eb7d275c808c26a37f0878e0b66be1d9
Author: staraz <staraz@chromium.org>
Date: Fri May 19 17:33:58 2017

Add CompositorFrameSinkClientBinding To Be Used By FrameGenerator

Added CompositorFrameSinkClientBinding interface.
CompositorFrameSinkClientBinding's default implementation holds interface
pointers to DisplayPrivate and MojoCompositorFrameSink. It binds FrameGenerator
to a MojoCompositorFrameSinkClient request. PlatformDisplayDefault sets up the
mojo connections before passing them to the binding object.

FrameGenerator unit tests use a mock of CompositorFrameSinkClientBinding to keep
track of the submitted frames.

FrameGenerator no longer uses cc::CompositorFrameSink after this CL.
cc::CompositorFrameSink should not be used by anything other than LayerTreeHost.

BUG= 721810 

Review-Url: https://codereview.chromium.org/2890913002
Cr-Commit-Position: refs/heads/master@{#473231}

[modify] https://crrev.com/0bcca1e6eb7d275c808c26a37f0878e0b66be1d9/services/ui/ws/BUILD.gn
[add] https://crrev.com/0bcca1e6eb7d275c808c26a37f0878e0b66be1d9/services/ui/ws/compositor_frame_sink_client_binding.cc
[add] https://crrev.com/0bcca1e6eb7d275c808c26a37f0878e0b66be1d9/services/ui/ws/compositor_frame_sink_client_binding.h
[delete] https://crrev.com/97d4d455f11785e8681ad01335b9239032c658ba/services/ui/ws/display_client_compositor_frame_sink.cc
[delete] https://crrev.com/97d4d455f11785e8681ad01335b9239032c658ba/services/ui/ws/display_client_compositor_frame_sink.h
[modify] https://crrev.com/0bcca1e6eb7d275c808c26a37f0878e0b66be1d9/services/ui/ws/frame_generator.cc
[modify] https://crrev.com/0bcca1e6eb7d275c808c26a37f0878e0b66be1d9/services/ui/ws/frame_generator.h
[modify] https://crrev.com/0bcca1e6eb7d275c808c26a37f0878e0b66be1d9/services/ui/ws/frame_generator_unittest.cc
[modify] https://crrev.com/0bcca1e6eb7d275c808c26a37f0878e0b66be1d9/services/ui/ws/platform_display_default.cc