Report if video capturing meets output protection requirement.

media/base/video_capturer_source.h

Index: media/base/video_capturer_source.h
diff --git a/media/base/video_capturer_source.h b/media/base/video_capturer_source.h
index ddec90c6599b26b564984e0b347d22472b4ca0df..4154303c1efc5acab027ddf56cc8b48cd32bf004 100644
--- a/media/base/video_capturer_source.h
+++ b/media/base/video_capturer_source.h
@@ -86,6 +86,10 @@ class MEDIA_EXPORT VideoCapturerSource {
   // successfully, then |new_frame_callback| should be called with a frame.
   virtual void RequestRefreshFrame() {}
 
+  // Notifies source the capturing link is secure. This is required by content
+  // output protection.
+  virtual void SetCapturingLinkSecured(bool is_secure) {}

[miu, 2016/04/26 01:25:14]

Do we need this in the interface definition?  It seems like this is side-detail
that only applies to the MediaStream framework in libcontent (and src/chrome
code).

[xjz, 2016/04/29 00:11:42]

Done. Removed the definition.

+
   // Stops capturing frames and clears all callbacks including the
   // SupportedFormatsCallback callback. Note that queued frame callbacks
   // may still occur after this call, so the caller must take care to