Reland "[Video Capture] Switch usage in Chromium Browser process to the new multi-client API"

This is a reland of 86e7aa883c95d551a450f71dc346fca4e31ea672

Revert was due to flaky test failures on MacOS 10.12.
The flakiness already existed before this CL.
The flaky test has been disabled.
https://chromium-review.googlesource.com/c/chromium/src/+/1501213

This reland is identical to the original attempt.

[email protected], [email protected]

Original change's description:
> [Video Capture] Switch usage in Chromium Browser process to the new multi-client API
>
> The video capture service offers a new API for opening capture devices
> in a way that allows them to be shared by multiple clients. This CL
> switches one such client, i.e. the Chromium Browser process, over to
> that new API. This enables other clients to share access to capture
> devices with the Chromium Browser process.
>
> Design Doc: https://docs.google.com/document/d/1mYnsZfLBRmbsDpUtfb6C7dzhfw2Kcxg_-uiG_6MnWVQ/edit?usp=sharing
>
> Test: content_browsertests --gtest_filter=WebRtcVideoCaptureSharedDeviceBrowserTest.*
> Bug: 783442
> Change-Id: I9c236f03e315cdafdc07429f3213fa4d11b43b34
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1399454
> Commit-Queue: Christian Fremerey <[email protected]>
> Reviewed-by: Mustafa Emre Acer <[email protected]>
> Reviewed-by: Emircan Uysaler <[email protected]>
> Cr-Commit-Position: refs/heads/master@{#637405}

Bug: 783442
Change-Id: I7dca38334bc78e400daa311fa0444173add9548d
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1504230
Commit-Queue: Christian Fremerey <[email protected]>
Reviewed-by: Mustafa Emre Acer <[email protected]>
Reviewed-by: Christian Fremerey <[email protected]>
Cr-Commit-Position: refs/heads/master@{#637873}
diff --git a/content/browser/BUILD.gn b/content/browser/BUILD.gn
index e607da8..e044abc 100644
--- a/content/browser/BUILD.gn
+++ b/content/browser/BUILD.gn
@@ -1492,8 +1492,8 @@
     "renderer_host/media/old_render_frame_audio_output_stream_factory.h",
     "renderer_host/media/peer_connection_tracker_host.cc",
     "renderer_host/media/peer_connection_tracker_host.h",
-    "renderer_host/media/ref_counted_video_capture_factory.cc",
-    "renderer_host/media/ref_counted_video_capture_factory.h",
+    "renderer_host/media/ref_counted_video_source_provider.cc",
+    "renderer_host/media/ref_counted_video_source_provider.h",
     "renderer_host/media/render_frame_audio_input_stream_factory.cc",
     "renderer_host/media/render_frame_audio_input_stream_factory.h",
     "renderer_host/media/render_frame_audio_output_stream_factory.cc",