This is basically reverting the refactor that added ContextProviderFactory, right? sgtm

khushalsagar: Any updates on this? You mentioned you'd try to get to this this week.

Ah sorry, I'm on it. Another thing here was that requesting the GpuChannelHost from BrowserGpuChannelHostFactory can get reentrant on shutdown, because in the callback the caller sees a null host and makes another request: https://cs.chromium.org/chromium/src/content/browser/gpu/browser_gpu_channel_host_factory.cc?type=cs&l=256

When I wrote the ContextProviderFactory I added an enum to the callback to indicate why the host was null so we don't get more requests on shutdown, may be that should be on GpuChannelEstablishFactory itself?

CL in review: https://codereview.chromium.org/2686243002/

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/31690fb03a1ca682147c4e1f81a7d8479c88a233

commit 31690fb03a1ca682147c4e1f81a7d8479c88a233
Author: khushalsagar <khushalsagar@chromium.org>
Date: Tue Feb 28 23:23:48 2017

content/ui[Android]: Remove ContextProviderFactory.

The class was added in ui/ to expose the compositor dependencies needed
by blimp, which is no longer necessary. The change removes the interface
and the implementation from content with the functionality added to
CompositorImpl.

Also, the logic for shutdown in GpuChannelEstablishFactory can currently
be reentrant, since the factory loops over all pending callbacks, and
running the callbacks with a null host can have the caller retry and add
to this list. This makes sure that the factory doesn't add any more
requests during shutdown.

BUG= 684072 
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:linux_site_isolation

Review-Url: https://codereview.chromium.org/2686243002
Cr-Commit-Position: refs/heads/master@{#453738}

[modify] https://crrev.com/31690fb03a1ca682147c4e1f81a7d8479c88a233/content/browser/BUILD.gn
[modify] https://crrev.com/31690fb03a1ca682147c4e1f81a7d8479c88a233/content/browser/browser_main_loop.cc
[modify] https://crrev.com/31690fb03a1ca682147c4e1f81a7d8479c88a233/content/browser/compositor/surface_utils.cc
[modify] https://crrev.com/31690fb03a1ca682147c4e1f81a7d8479c88a233/content/browser/frame_host/render_widget_host_view_child_frame_unittest.cc
[modify] https://crrev.com/31690fb03a1ca682147c4e1f81a7d8479c88a233/content/browser/frame_host/render_widget_host_view_guest_unittest.cc
[modify] https://crrev.com/31690fb03a1ca682147c4e1f81a7d8479c88a233/content/browser/gpu/browser_gpu_channel_host_factory.cc
[modify] https://crrev.com/31690fb03a1ca682147c4e1f81a7d8479c88a233/content/browser/gpu/gpu_ipc_browsertests.cc
[modify] https://crrev.com/31690fb03a1ca682147c4e1f81a7d8479c88a233/content/browser/renderer_host/compositor_impl_android.cc
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[modify] https://crrev.com/31690fb03a1ca682147c4e1f81a7d8479c88a233/content/browser/renderer_host/render_widget_host_view_android.cc
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[modify] https://crrev.com/31690fb03a1ca682147c4e1f81a7d8479c88a233/content/public/test/test_renderer_host.h
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[modify] https://crrev.com/31690fb03a1ca682147c4e1f81a7d8479c88a233/content/test/test_render_view_host.cc
[modify] https://crrev.com/31690fb03a1ca682147c4e1f81a7d8479c88a233/services/ui/public/cpp/gpu/command_buffer_metrics.cc
[modify] https://crrev.com/31690fb03a1ca682147c4e1f81a7d8479c88a233/services/ui/public/cpp/gpu/command_buffer_metrics.h
[modify] https://crrev.com/31690fb03a1ca682147c4e1f81a7d8479c88a233/services/ui/public/cpp/gpu/gpu.cc
[modify] https://crrev.com/31690fb03a1ca682147c4e1f81a7d8479c88a233/tools/metrics/histograms/histograms.xml
[modify] https://crrev.com/31690fb03a1ca682147c4e1f81a7d8479c88a233/ui/android/BUILD.gn
[delete] https://crrev.com/1a04e1cf3d4912300d625a57318bc6f2ba53ba79/ui/android/context_provider_factory.cc
[delete] https://crrev.com/1a04e1cf3d4912300d625a57318bc6f2ba53ba79/ui/android/context_provider_factory.h
[modify] https://crrev.com/31690fb03a1ca682147c4e1f81a7d8479c88a233/ui/android/delegated_frame_host_android.cc
[modify] https://crrev.com/31690fb03a1ca682147c4e1f81a7d8479c88a233/ui/android/delegated_frame_host_android.h