Add srcObject attribute of type MediaStream to HTMLMediaElement.

third_party/WebKit/Source/modules/srcobject/HTMLMediaElementSrcObject.h

Index: third_party/WebKit/Source/modules/srcobject/HTMLMediaElementSrcObject.h
diff --git a/third_party/WebKit/Source/modules/srcobject/HTMLMediaElementSrcObject.h b/third_party/WebKit/Source/modules/srcobject/HTMLMediaElementSrcObject.h
new file mode 100644
index 0000000000000000000000000000000000000000..8451a17ca0c40882f523eb8b78e1767de89bb055
--- /dev/null
+++ b/third_party/WebKit/Source/modules/srcobject/HTMLMediaElementSrcObject.h
@@ -0,0 +1,25 @@
+// Copyright 2016 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.
+
+#ifndef HTMLMediaElementSrcObject_h
+#define HTMLMediaElementSrcObject_h
+
+#include "modules/ModulesExport.h"
+#include "wtf/Allocator.h"
+
+namespace blink {
+
+class MediaStream;
+class HTMLMediaElement;
+
+class MODULES_EXPORT HTMLMediaElementSrcObject {
+    STATIC_ONLY(HTMLMediaElementSrcObject);
+public:
+    static MediaStream* srcObject(HTMLMediaElement&);
+    static void setSrcObject(HTMLMediaElement&, MediaStream*);
+};
+
+} // namespace blink
+
+#endif