The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/ab81ed65a4d788b68cccfa6c25817864bf9c9a50

commit ab81ed65a4d788b68cccfa6c25817864bf9c9a50
Author: braveyao <braveyao@chromium.org>
Date: Wed Oct 03 17:37:51 2018

[desktopCapture] stop capture when screen is locked.

To support the implementation of getDisplayMedia() API in chromium, it's
required to stop screensharing when screen is locked on desktop platforms.

This cl is to add an interface to observe the screen lock event into
content/browser and let VideoCaptureManager stop desktopCapture sessions
on screenlock event.

Note: It's done on Win/OSX/CrOS at present. Still tring to find a solid
way on Linux.

Bug: 887585
Change-Id: Ibe65d51c68e07f632a851f22d2ba6777a527204d
Reviewed-on: https://chromium-review.googlesource.com/1241160
Reviewed-by: Christian Fremerey <chfremer@chromium.org>
Reviewed-by: Dan Erat <derat@chromium.org>
Reviewed-by: Xiyuan Xia <xiyuan@chromium.org>
Reviewed-by: Avi Drissman <avi@chromium.org>
Commit-Queue: Weiyong Yao <braveyao@chromium.org>
Cr-Commit-Position: refs/heads/master@{#596273}
[modify] https://crrev.com/ab81ed65a4d788b68cccfa6c25817864bf9c9a50/chrome/browser/chromeos/chrome_browser_main_chromeos.cc
[modify] https://crrev.com/ab81ed65a4d788b68cccfa6c25817864bf9c9a50/content/browser/BUILD.gn
[modify] https://crrev.com/ab81ed65a4d788b68cccfa6c25817864bf9c9a50/content/browser/DEPS
[modify] https://crrev.com/ab81ed65a4d788b68cccfa6c25817864bf9c9a50/content/browser/browser_main_loop.cc
[modify] https://crrev.com/ab81ed65a4d788b68cccfa6c25817864bf9c9a50/content/browser/browser_main_loop.h
[modify] https://crrev.com/ab81ed65a4d788b68cccfa6c25817864bf9c9a50/content/browser/renderer_host/media/media_devices_dispatcher_host.cc
[modify] https://crrev.com/ab81ed65a4d788b68cccfa6c25817864bf9c9a50/content/browser/renderer_host/media/media_devices_manager.cc
[modify] https://crrev.com/ab81ed65a4d788b68cccfa6c25817864bf9c9a50/content/browser/renderer_host/media/media_stream_manager.cc
[modify] https://crrev.com/ab81ed65a4d788b68cccfa6c25817864bf9c9a50/content/browser/renderer_host/media/video_capture_manager.cc
[modify] https://crrev.com/ab81ed65a4d788b68cccfa6c25817864bf9c9a50/content/browser/renderer_host/media/video_capture_manager.h
[modify] https://crrev.com/ab81ed65a4d788b68cccfa6c25817864bf9c9a50/content/browser/renderer_host/media/video_capture_manager_unittest.cc
[add] https://crrev.com/ab81ed65a4d788b68cccfa6c25817864bf9c9a50/content/browser/screenlock_monitor/OWNERS
[add] https://crrev.com/ab81ed65a4d788b68cccfa6c25817864bf9c9a50/content/browser/screenlock_monitor/screenlock_monitor.cc
[add] https://crrev.com/ab81ed65a4d788b68cccfa6c25817864bf9c9a50/content/browser/screenlock_monitor/screenlock_monitor.h
[add] https://crrev.com/ab81ed65a4d788b68cccfa6c25817864bf9c9a50/content/browser/screenlock_monitor/screenlock_monitor_device_source.cc
[add] https://crrev.com/ab81ed65a4d788b68cccfa6c25817864bf9c9a50/content/browser/screenlock_monitor/screenlock_monitor_device_source.h
[add] https://crrev.com/ab81ed65a4d788b68cccfa6c25817864bf9c9a50/content/browser/screenlock_monitor/screenlock_monitor_device_source_chromeos.cc
[add] https://crrev.com/ab81ed65a4d788b68cccfa6c25817864bf9c9a50/content/browser/screenlock_monitor/screenlock_monitor_device_source_mac.mm
[add] https://crrev.com/ab81ed65a4d788b68cccfa6c25817864bf9c9a50/content/browser/screenlock_monitor/screenlock_monitor_device_source_win.cc
[add] https://crrev.com/ab81ed65a4d788b68cccfa6c25817864bf9c9a50/content/browser/screenlock_monitor/screenlock_monitor_source.cc
[add] https://crrev.com/ab81ed65a4d788b68cccfa6c25817864bf9c9a50/content/browser/screenlock_monitor/screenlock_monitor_source.h
[add] https://crrev.com/ab81ed65a4d788b68cccfa6c25817864bf9c9a50/content/browser/screenlock_monitor/screenlock_monitor_unittest.cc
[modify] https://crrev.com/ab81ed65a4d788b68cccfa6c25817864bf9c9a50/content/public/browser/BUILD.gn
[add] https://crrev.com/ab81ed65a4d788b68cccfa6c25817864bf9c9a50/content/public/browser/screenlock_observer.h
[modify] https://crrev.com/ab81ed65a4d788b68cccfa6c25817864bf9c9a50/content/public/common/media_stream_request.cc
[modify] https://crrev.com/ab81ed65a4d788b68cccfa6c25817864bf9c9a50/content/public/common/media_stream_request.h
[modify] https://crrev.com/ab81ed65a4d788b68cccfa6c25817864bf9c9a50/content/test/BUILD.gn