+yitingc@ for privacy check. As said in the intent to ship, expectation is that the privacy cost is very low and the added entropy insignificant as high color depth would correlate with other information.

+chrishtr@

We just discussed this today.

We don't see the fingerprinting concern as blocking. But we'd like to know any known use cases for this capability? And also if the team has any insight of display models distribution, so we known the likelihood of some super rare display devices being linked to either a very small group of users or individuals.

Our implementation will only report 48 when --enable-hdr is toggled and 24 otherwise. We have no plans to do something different at the moment. Websites need to know that HDR is on and this information will not be the only one giving up that HDR is available.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/7c149655e1546c3bb4478f4dca931e5ad35d4073

commit 7c149655e1546c3bb4478f4dca931e5ad35d4073
Author: mlamouri <mlamouri@chromium.org>
Date: Fri Mar 24 00:00:09 2017

Display: set color_depth and depth_per_component value based on kEnableHDROutput

This is also update the aura code creating the ScreenInfo to use the
value reported by display::Display instead of hardcoding it as
display::Display was doing the same thing. It is more consistent too as
the Mac implementation was already doing this.

This is also moving the kEnableHDROutput from ui/base/ to ui/display/
because ui/display/ can't depend on ui/base/ and it only moves the
dependency of ui/compositor/ from ui/base/ to ui/display/.

In the future, we should set the values on display::Display instead of
hardcoding too values.

Intent to Ship:
https://groups.google.com/a/chromium.org/d/msg/blink-dev/c-b866DUg10/MxS1WTWfBgAJ

BUG= 701466 
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.android:android_optional_gpu_tests_rel;master.tryserver.chromium.linux:linux_optional_gpu_tests_rel;master.tryserver.chromium.win:win_optional_gpu_tests_rel

Review-Url: https://codereview.chromium.org/2742383006
Cr-Commit-Position: refs/heads/master@{#459288}

[modify] https://crrev.com/7c149655e1546c3bb4478f4dca931e5ad35d4073/content/browser/gpu/gpu_process_host.cc
[modify] https://crrev.com/7c149655e1546c3bb4478f4dca931e5ad35d4073/content/browser/media/media_canplaytype_browsertest.cc
[modify] https://crrev.com/7c149655e1546c3bb4478f4dca931e5ad35d4073/content/browser/renderer_host/render_view_host_impl.cc
[modify] https://crrev.com/7c149655e1546c3bb4478f4dca931e5ad35d4073/content/browser/renderer_host/render_widget_host_impl.cc
[modify] https://crrev.com/7c149655e1546c3bb4478f4dca931e5ad35d4073/content/browser/web_contents/web_contents_view_aura.cc
[modify] https://crrev.com/7c149655e1546c3bb4478f4dca931e5ad35d4073/content/browser/web_contents/web_contents_view_aura_unittest.cc
[modify] https://crrev.com/7c149655e1546c3bb4478f4dca931e5ad35d4073/content/renderer/media/render_media_client.cc
[modify] https://crrev.com/7c149655e1546c3bb4478f4dca931e5ad35d4073/content/renderer/render_thread_impl.cc
[modify] https://crrev.com/7c149655e1546c3bb4478f4dca931e5ad35d4073/gpu/ipc/service/BUILD.gn
[modify] https://crrev.com/7c149655e1546c3bb4478f4dca931e5ad35d4073/gpu/ipc/service/DEPS
[modify] https://crrev.com/7c149655e1546c3bb4478f4dca931e5ad35d4073/gpu/ipc/service/child_window_surface_win.cc
[modify] https://crrev.com/7c149655e1546c3bb4478f4dca931e5ad35d4073/gpu/ipc/service/direct_composition_surface_win.cc
[modify] https://crrev.com/7c149655e1546c3bb4478f4dca931e5ad35d4073/media/gpu/BUILD.gn
[modify] https://crrev.com/7c149655e1546c3bb4478f4dca931e5ad35d4073/media/gpu/DEPS
[modify] https://crrev.com/7c149655e1546c3bb4478f4dca931e5ad35d4073/media/gpu/dxva_video_decode_accelerator_win.cc
[modify] https://crrev.com/7c149655e1546c3bb4478f4dca931e5ad35d4073/ui/base/ui_base_switches.cc
[modify] https://crrev.com/7c149655e1546c3bb4478f4dca931e5ad35d4073/ui/base/ui_base_switches.h
[modify] https://crrev.com/7c149655e1546c3bb4478f4dca931e5ad35d4073/ui/compositor/BUILD.gn
[modify] https://crrev.com/7c149655e1546c3bb4478f4dca931e5ad35d4073/ui/compositor/DEPS
[modify] https://crrev.com/7c149655e1546c3bb4478f4dca931e5ad35d4073/ui/compositor/compositor.cc
[modify] https://crrev.com/7c149655e1546c3bb4478f4dca931e5ad35d4073/ui/display/display.cc
[modify] https://crrev.com/7c149655e1546c3bb4478f4dca931e5ad35d4073/ui/display/display_switches.cc
[modify] https://crrev.com/7c149655e1546c3bb4478f4dca931e5ad35d4073/ui/display/display_switches.h
[modify] https://crrev.com/7c149655e1546c3bb4478f4dca931e5ad35d4073/ui/display/display_unittest.cc