During testing, an error occurred while starting Media Remoting, and this left the user with a broken video player in the page. Instead, the fallback-to-mirroring should have engaged and the video player in the page should have continued normally by falling-back to the normal local media::Renderer (plus traditional tab capture mirroring).

The error occurred while the media pipeline was initializing the CourierRenderer, and the CourierRenderer reported this failure back to the media pipeline. Instead, it should always report success to the media pipeline, and then become a no-op renderer after that point. The idea: Because of the Media Remoting error, the Media Remoting session will soon end, and the CourierRenderer will be switched with a normal local media::Renderer. We want the media pipeline to be in a non-error state so that it will happily switch to using this new local renderer.