Report if video capturing meets output protection requirement.

content/renderer/media/media_stream_video_track.cc

 // Copyright 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "content/renderer/media/media_stream_video_track.h"
 
 #include <utility>
 
 #include "base/bind.h"
 #include "base/location.h"
@@ skipping 211 matching lines @@
 MediaStreamVideoTrack::MediaStreamVideoTrack(
     MediaStreamVideoSource* source,
     const blink::WebMediaConstraints& constraints,
     const MediaStreamVideoSource::ConstraintsCallback& callback,
     bool enabled)
     : MediaStreamTrack(true),
       frame_deliverer_(
           new MediaStreamVideoTrack::FrameDeliverer(source->io_task_runner(),
                                                     enabled)),
       constraints_(constraints),
-      source_(source) {
+      source_(source),
+      video_capturing_link_secured_(true) {
   DCHECK(!constraints.isNull());
   source->AddTrack(this,
                    base::Bind(
                        &MediaStreamVideoTrack::FrameDeliverer::DeliverFrameOnIO,
                        frame_deliverer_),
                    constraints, callback);
 }
 
 MediaStreamVideoTrack::~MediaStreamVideoTrack() {
   DCHECK(main_render_thread_checker_.CalledOnValidThread());
@@ skipping 38 matching lines @@
   OnReadyStateChanged(blink::WebMediaStreamSource::ReadyStateEnded);
 }
 
 void MediaStreamVideoTrack::OnReadyStateChanged(
     blink::WebMediaStreamSource::ReadyState state) {
   DCHECK(main_render_thread_checker_.CalledOnValidThread());
   for (auto* sink : sinks_)
     sink->OnReadyStateChanged(state);
 }
 
+void MediaStreamVideoTrack::SetVideoSinkSecured(bool is_secure) {
+  DCHECK(main_render_thread_checker_.CalledOnValidThread());
+  video_capturing_link_secured_ &= is_secure;

[miu, 2016/04/16 00:05:29]

You need to track these booleans individually.  For example, this logic fails
for this sequence:

1. Add secure sink.  Track is secure.
2. Add insecure sink.  Track is no longer secure.
3. Remove insecure sink.  Track should be secure again (because only a secure
sink remains connected).

This also needs to be fixed in the MediaStreamVideoSources.

[xjz, 2016/04/21 23:50:45]

Done.

+  if (source_)
+    source_->SetCapturingLinkSecured(video_capturing_link_secured_);
+}
+
 }  // namespace content