I plan to add a new function CreateCompositorFrameSink in aura::Window, and use it to create frame
sink for the aura::window. So the user of it doesn't need to know and access ContextFactory*.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/4c5a2a2c64c2b54355139eb9970fb1992e8363bd

commit 4c5a2a2c64c2b54355139eb9970fb1992e8363bd
Author: penghuang <penghuang@chromium.org>
Date: Wed May 10 04:41:55 2017

Implement aura::Window::CreateCompositorFrameSink()

Currently, the exo creates cc::CompositorFrameSinkSupport by itself.
To create cc::CompositorFrameSinkSupport, exo has to access
ContextFactoryPrivate for allocating a FrameSinkId and accessing
cc::SurfaceManager, etc. But all those objects are not available in
Mus clients, so the exo doesn't work in Mushrome and Mustash
To support mushrome and mustash, this CL adds
aura::Window::CreateCompositorFrameSink(), this function hides the
detail of CompositorFrameSink creation within Cash and Mus.

Note: this CL only implements aura::Window::CreateCompositorFrameSink()
for Cash. A follow up CL will implements it for Mus.

BUG= 718443 
TEST=tested exo with weston-terminal, wayland_rects_client
CQ_INCLUDE_TRYBOTS=master.tryserver.blink:linux_trusty_blink_rel

Review-Url: https://codereview.chromium.org/2868473002
Cr-Commit-Position: refs/heads/master@{#470450}

[modify] https://crrev.com/4c5a2a2c64c2b54355139eb9970fb1992e8363bd/components/exo/BUILD.gn
[modify] https://crrev.com/4c5a2a2c64c2b54355139eb9970fb1992e8363bd/components/exo/buffer.cc
[modify] https://crrev.com/4c5a2a2c64c2b54355139eb9970fb1992e8363bd/components/exo/buffer.h
[modify] https://crrev.com/4c5a2a2c64c2b54355139eb9970fb1992e8363bd/components/exo/buffer_unittest.cc
[delete] https://crrev.com/25488964c9f5595d2f70edf0f25c502e9acdc281/components/exo/compositor_frame_sink.cc
[delete] https://crrev.com/25488964c9f5595d2f70edf0f25c502e9acdc281/components/exo/compositor_frame_sink.h
[modify] https://crrev.com/4c5a2a2c64c2b54355139eb9970fb1992e8363bd/components/exo/compositor_frame_sink_holder.cc
[modify] https://crrev.com/4c5a2a2c64c2b54355139eb9970fb1992e8363bd/components/exo/compositor_frame_sink_holder.h
[modify] https://crrev.com/4c5a2a2c64c2b54355139eb9970fb1992e8363bd/components/exo/surface.cc
[modify] https://crrev.com/4c5a2a2c64c2b54355139eb9970fb1992e8363bd/components/exo/surface.h
[modify] https://crrev.com/4c5a2a2c64c2b54355139eb9970fb1992e8363bd/ui/aura/BUILD.gn
[modify] https://crrev.com/4c5a2a2c64c2b54355139eb9970fb1992e8363bd/ui/aura/DEPS
[modify] https://crrev.com/4c5a2a2c64c2b54355139eb9970fb1992e8363bd/ui/aura/env.cc
[add] https://crrev.com/4c5a2a2c64c2b54355139eb9970fb1992e8363bd/ui/aura/local/DEPS
[add] https://crrev.com/4c5a2a2c64c2b54355139eb9970fb1992e8363bd/ui/aura/local/compositor_frame_sink_local.cc
[add] https://crrev.com/4c5a2a2c64c2b54355139eb9970fb1992e8363bd/ui/aura/local/compositor_frame_sink_local.h
[add] https://crrev.com/4c5a2a2c64c2b54355139eb9970fb1992e8363bd/ui/aura/local/window_port_local.cc
[rename] https://crrev.com/4c5a2a2c64c2b54355139eb9970fb1992e8363bd/ui/aura/local/window_port_local.h
[modify] https://crrev.com/4c5a2a2c64c2b54355139eb9970fb1992e8363bd/ui/aura/mus/window_port_mus.cc
[modify] https://crrev.com/4c5a2a2c64c2b54355139eb9970fb1992e8363bd/ui/aura/mus/window_port_mus.h
[modify] https://crrev.com/4c5a2a2c64c2b54355139eb9970fb1992e8363bd/ui/aura/test/aura_test_helper.cc
[modify] https://crrev.com/4c5a2a2c64c2b54355139eb9970fb1992e8363bd/ui/aura/window.cc
[modify] https://crrev.com/4c5a2a2c64c2b54355139eb9970fb1992e8363bd/ui/aura/window.h
[modify] https://crrev.com/4c5a2a2c64c2b54355139eb9970fb1992e8363bd/ui/aura/window_port.h
[delete] https://crrev.com/25488964c9f5595d2f70edf0f25c502e9acdc281/ui/aura/window_port_local.cc