The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/12e259d5a209aa333c5cf748bffcad031e173786

commit 12e259d5a209aa333c5cf748bffcad031e173786
Author: sadrul <sadrul@chromium.org>
Date: Fri Aug 19 01:36:58 2016

services/ui: Use a gpu::GpuChannelHost when creating ui::OutputSurface.

There are two users of ui::OutputSurface, and this change makes things more
correct for both. Because:

. renderer: RenderThreadImpl already creates the GpuChannelHost instance
  synchronously before creating the OutputSurface in non-mus. This does the same
  for mus, instead of potentially delaying the GpuChannelHost creation (or doing
  it in the compositor thread).

. ui or browser: Before this change, SurfaceContextFactory would create the
  OutputSurface, and immediately set it on the Compositor, leading to the
  synchronous creation of GpuChannelHost. This change just makes that more
  obvious, and creates the GpuChannelHost synchronously first before creating
  the OutputSurface.

This change also makes it possible to simplify ui::GpuService to not be usable
from multiple threads.

BUG= 638647 

Review-Url: https://codereview.chromium.org/2257693002
Cr-Commit-Position: refs/heads/master@{#413011}

[modify] https://crrev.com/12e259d5a209aa333c5cf748bffcad031e173786/content/renderer/mus/render_widget_mus_connection.cc
[modify] https://crrev.com/12e259d5a209aa333c5cf748bffcad031e173786/content/renderer/mus/render_widget_mus_connection.h
[modify] https://crrev.com/12e259d5a209aa333c5cf748bffcad031e173786/content/renderer/render_thread_impl.cc
[modify] https://crrev.com/12e259d5a209aa333c5cf748bffcad031e173786/services/ui/demo/bitmap_uploader.cc
[modify] https://crrev.com/12e259d5a209aa333c5cf748bffcad031e173786/services/ui/demo/bitmap_uploader.h
[modify] https://crrev.com/12e259d5a209aa333c5cf748bffcad031e173786/services/ui/demo/mus_demo.cc
[modify] https://crrev.com/12e259d5a209aa333c5cf748bffcad031e173786/services/ui/public/cpp/context_provider.cc
[modify] https://crrev.com/12e259d5a209aa333c5cf748bffcad031e173786/services/ui/public/cpp/context_provider.h
[modify] https://crrev.com/12e259d5a209aa333c5cf748bffcad031e173786/services/ui/public/cpp/gles2_context.cc
[modify] https://crrev.com/12e259d5a209aa333c5cf748bffcad031e173786/services/ui/public/cpp/gles2_context.h
[modify] https://crrev.com/12e259d5a209aa333c5cf748bffcad031e173786/services/ui/public/cpp/output_surface.cc
[modify] https://crrev.com/12e259d5a209aa333c5cf748bffcad031e173786/services/ui/public/cpp/output_surface.h
[modify] https://crrev.com/12e259d5a209aa333c5cf748bffcad031e173786/ui/views/mus/surface_context_factory.cc

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/75f7dde87bfea8b3eab80814e320c2c528d77224

commit 75f7dde87bfea8b3eab80814e320c2c528d77224
Author: sadrul <sadrul@chromium.org>
Date: Mon Aug 22 23:37:24 2016

services/ui: Allow injecting the IO thread task runner for gpu channel.

Instead of always creating a new thread, allow injecting the IO thread
task runner into the ui::GpuService for the gpu::GpuChannelHost it
creates. This allows chrome browser and renderer processes to inject
their existing IO thread's task runner. A new thread is created only for
other mus apps that do not have their own IO thread.

BUG= 638647 

Review-Url: https://codereview.chromium.org/2249413004
Cr-Commit-Position: refs/heads/master@{#413583}

[modify] https://crrev.com/75f7dde87bfea8b3eab80814e320c2c528d77224/ash/mus/window_manager_application.cc
[modify] https://crrev.com/75f7dde87bfea8b3eab80814e320c2c528d77224/chrome/browser/ui/views/chrome_browser_main_extra_parts_views.cc
[modify] https://crrev.com/75f7dde87bfea8b3eab80814e320c2c528d77224/content/renderer/render_thread_impl.cc
[modify] https://crrev.com/75f7dde87bfea8b3eab80814e320c2c528d77224/services/ui/demo/mus_demo.cc
[modify] https://crrev.com/75f7dde87bfea8b3eab80814e320c2c528d77224/services/ui/public/cpp/gpu_service.cc
[modify] https://crrev.com/75f7dde87bfea8b3eab80814e320c2c528d77224/services/ui/public/cpp/gpu_service.h
[modify] https://crrev.com/75f7dde87bfea8b3eab80814e320c2c528d77224/ui/views/mus/window_manager_connection.cc
[modify] https://crrev.com/75f7dde87bfea8b3eab80814e320c2c528d77224/ui/views/mus/window_manager_connection.h

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/46dc962ad711cfb0f576ff8a210e5bb25730071e

commit 46dc962ad711cfb0f576ff8a210e5bb25730071e
Author: sadrul <sadrul@chromium.org>
Date: Tue Aug 23 14:36:46 2016

services/ui: GpuService should only be used from a single thread.

Simplify GpuService, and make it usable from only one thread.

BUG= 638647 

Review-Url: https://codereview.chromium.org/2257713002
Cr-Commit-Position: refs/heads/master@{#413735}

[modify] https://crrev.com/46dc962ad711cfb0f576ff8a210e5bb25730071e/services/ui/public/cpp/gpu_service.cc
[modify] https://crrev.com/46dc962ad711cfb0f576ff8a210e5bb25730071e/services/ui/public/cpp/gpu_service.h