media: Use OnceClosure for DemuxerStreamAdapter::OnFatalError.

Switching to using a base::OnceClosure when calling
RemotingDataStreamSender::set_connection_error_handler as
it explicitly accepts a base::OnceClosure (see
mojo/public/cpp/bindings/interface_ptr.h).

TBR=erickung@chromium.org

Bug: 1007810
Change-Id: I02aa1ea954c961b1a1158fc817969d5404936e81
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1880147Reviewed-by: Chris Mumford <cmumford@google.com>
Commit-Queue: Chris Mumford <cmumford@google.com>
Cr-Commit-Position: refs/heads/master@{#714019}

media/remoting/demuxer_stream_adapter.cc

@@ -68,7 +68,7 @@ DemuxerStreamAdapter::DemuxerStreamAdapter(
 
   stream_sender_.Bind(std::move(stream_sender_info));
   stream_sender_.set_connection_error_handler(
-      base::Bind(&DemuxerStreamAdapter::OnFatalError,
+      base::BindOnce(&DemuxerStreamAdapter::OnFatalError,
                      weak_factory_.GetWeakPtr(), MOJO_PIPE_ERROR));
 }