Add SourceBuffer implementations of Audio/VideoTracks

third_party/WebKit/Source/modules/mediasource/VideoTrack.idl

Index: third_party/WebKit/Source/modules/mediasource/VideoTrack.idl
diff --git a/third_party/WebKit/Source/core/frame/NavigatorOnLine.idl b/third_party/WebKit/Source/modules/mediasource/VideoTrack.idl
similarity index 84%
copy from third_party/WebKit/Source/core/frame/NavigatorOnLine.idl
copy to third_party/WebKit/Source/modules/mediasource/VideoTrack.idl
index 94468aaeeedffbf3fd984d6229c3567c9012504b..4a2f3af0bb9afba68cc6b664133c6c5ba1d494be 100644
--- a/third_party/WebKit/Source/core/frame/NavigatorOnLine.idl
+++ b/third_party/WebKit/Source/modules/mediasource/VideoTrack.idl
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2013 Samsung Electronics. All rights reserved.
+ * Copyright (C) 2016 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
@@ -28,11 +28,11 @@
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
-// https://html.spec.whatwg.org/#navigator.online
+// http://www.w3.org/TR/media-source/#video-track-extensions
 
 [
-    NoInterfaceObject, // Always used on target of 'implements'
-    Exposed=(Window,Worker),
-] interface NavigatorOnLine {
-    readonly attribute boolean onLine;
+    RuntimeEnabled=AudioVideoTracks,
+    ImplementedAs=SourceBufferVideoTrack,
+] partial interface VideoTrack {
+    readonly attribute SourceBuffer? sourceBuffer;
 };