Use spec-compliant algorithm for video content-capture deviceId selection in getUserMedia.

content/renderer/media/user_media_client_impl.h

Index: content/renderer/media/user_media_client_impl.h
diff --git a/content/renderer/media/user_media_client_impl.h b/content/renderer/media/user_media_client_impl.h
index 9d198d9a5ea115be0434b942be5f48aa4d01c3ac..3c4a7c547f248da6d8f09db207088e2959fcf46a 100644
--- a/content/renderer/media/user_media_client_impl.h
+++ b/content/renderer/media/user_media_client_impl.h
@@ -39,6 +39,7 @@ class PeerConnectionDependencyFactory;
 class MediaStreamAudioSource;
 class MediaStreamDispatcher;
 class MediaStreamVideoSource;
+class VideoContentCaptureSourceSelectionResult;
 class VideoDeviceCaptureSourceSelectionResult;
 
 // UserMediaClientImpl is a delegate for the Media Stream GetUserMedia API.
@@ -317,6 +318,13 @@ class CONTENT_EXPORT UserMediaClientImpl
       const RequestSettings& request_settings,
       const VideoDeviceCaptureSourceSelectionResult& selection_result);
 
+  void FinalizeSelectVideoContentSourceSettings(
+      int request_id,
+      const blink::WebUserMediaRequest& user_media_request,
+      std::unique_ptr<StreamControls> controls,
+      const RequestSettings& request_settings,
+      const VideoContentCaptureSourceSelectionResult& selection_result);
+
   void FinalizeRequestUserMedia(
       int request_id,
       const blink::WebUserMediaRequest& user_media_request,