The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/432ae89464e986ed04bc5f6494509cd72384e2bf

commit 432ae89464e986ed04bc5f6494509cd72384e2bf
Author: Sergey Ulanov <sergeyu@chromium.org>
Date: Tue Jul 24 02:52:04 2018

[Fuchsia] Add VideoCaptureDeviceFactory stub

VideoCaptureSystemImpl expects to have non-null
VideoCaptureDeviceFactory, but it was getting nullptr value on Fuchsia.
As result the browser was crashing

Bug: 866669
Change-Id: I73ec5c850acdc392a7984f62d9f66edb0961809a
Reviewed-on: https://chromium-review.googlesource.com/1147514
Commit-Queue: Sergey Ulanov <sergeyu@chromium.org>
Reviewed-by: Christian Fremerey <chfremer@chromium.org>
Cr-Commit-Position: refs/heads/master@{#577415}
[modify] https://crrev.com/432ae89464e986ed04bc5f6494509cd72384e2bf/media/capture/BUILD.gn
[modify] https://crrev.com/432ae89464e986ed04bc5f6494509cd72384e2bf/media/capture/video/create_video_capture_device_factory.cc
[add] https://crrev.com/432ae89464e986ed04bc5f6494509cd72384e2bf/media/capture/video/fuchsia/video_capture_device_factory_fuchsia.cc
[add] https://crrev.com/432ae89464e986ed04bc5f6494509cd72384e2bf/media/capture/video/fuchsia/video_capture_device_factory_fuchsia.h
[modify] https://crrev.com/432ae89464e986ed04bc5f6494509cd72384e2bf/services/video_capture/device_factory_provider_impl.cc