From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Athul Iddya <athul@iddya.com>
Date: Fri, 14 Jul 2023 08:03:37 -0700
Subject: fix: use delegated generic capturer when available

When the generic capturer is used to fetch capture sources, the returned
ID will be arbitrarily prefixed with "screen" or "window" regardless of
the source type. If the window capturer is used to stream video when the
source was a screen or vice-versa, the stream fails to restart in
delegated capturers like PipeWire.

To fix this, use the generic capturer to fetch the media stream if it's
delegated and available. This does not cause any issues if the original
capturer was window or screen-specific, as the IDs remain valid for
generic capturer as well.

diff --git a/content/browser/media/capture/desktop_capture_device.cc b/content/browser/media/capture/desktop_capture_device.cc
index 693e14ee2a786b8a5fae335e08264a8a74d15c0d..e54a583fbd7645b7b3e6b64b6e143f932f22ba5b 100644
--- a/content/browser/media/capture/desktop_capture_device.cc
+++ b/content/browser/media/capture/desktop_capture_device.cc
@@ -822,8 +822,14 @@ std::unique_ptr<media::VideoCaptureDevice> DesktopCaptureDevice::Create(
               DesktopCapturerLacros::CaptureType::kScreen,
               webrtc::DesktopCaptureOptions());
 #else
-      std::unique_ptr<webrtc::DesktopCapturer> screen_capturer(
-          webrtc::DesktopCapturer::CreateScreenCapturer(options));
+      std::unique_ptr<webrtc::DesktopCapturer> screen_capturer;
+      if (auto generic_capturer =
+              webrtc::DesktopCapturer::CreateGenericCapturer(options);
+          generic_capturer && generic_capturer->GetDelegatedSourceListController()) {
+        screen_capturer = std::move(generic_capturer);
+      } else {
+        screen_capturer = webrtc::DesktopCapturer::CreateScreenCapturer(options);
+      }
 #endif
       if (screen_capturer && screen_capturer->SelectSource(source.id)) {
         capturer = std::make_unique<webrtc::DesktopAndCursorComposer>(
@@ -842,8 +848,14 @@ std::unique_ptr<media::VideoCaptureDevice> DesktopCaptureDevice::Create(
           new DesktopCapturerLacros(DesktopCapturerLacros::CaptureType::kWindow,
                                     webrtc::DesktopCaptureOptions()));
 #else
-      std::unique_ptr<webrtc::DesktopCapturer> window_capturer =
-          webrtc::DesktopCapturer::CreateWindowCapturer(options);
+      std::unique_ptr<webrtc::DesktopCapturer> window_capturer;
+      if (auto generic_capturer =
+              webrtc::DesktopCapturer::CreateGenericCapturer(options);
+          generic_capturer && generic_capturer->GetDelegatedSourceListController()) {
+        window_capturer = std::move(generic_capturer);
+      } else {
+        window_capturer = webrtc::DesktopCapturer::CreateWindowCapturer(options);
+      }
 #endif
       if (window_capturer && window_capturer->SelectSource(source.id)) {
         capturer = std::make_unique<webrtc::DesktopAndCursorComposer>(
