Add new files for VideoSourceBase to roll into Chrome in preparation for implementatin.

webrtc/media/base/videosourcebase.h

Index: webrtc/media/base/videosourcebase.h
diff --git a/webrtc/modules/audio_coding/acm2/acm_neteq_unittest.cc b/webrtc/media/base/videosourcebase.h
similarity index 59%
copy from webrtc/modules/audio_coding/acm2/acm_neteq_unittest.cc
copy to webrtc/media/base/videosourcebase.h
index 607b933deb6bc7e6a75daeddfe488b831f69d750..61dfff3cb4c60cb54af917deadf02348999648c3 100644
--- a/webrtc/modules/audio_coding/acm2/acm_neteq_unittest.cc
+++ b/webrtc/media/base/videosourcebase.h
@@ -1,5 +1,5 @@
 /*
- *  Copyright (c) 2012 The WebRTC project authors. All Rights Reserved.
+ *  Copyright (c) 2016 The WebRTC project authors. All Rights Reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
@@ -8,8 +8,9 @@
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
-// This file contains unit tests for ACM's NetEQ wrapper (class ACMNetEQ).
+#ifndef WEBRTC_MEDIA_BASE_VIDEOSOURCEBASE_H_
+#define WEBRTC_MEDIA_BASE_VIDEOSOURCEBASE_H_
 
-namespace webrtc {
+// TODO(perkj): Add implementation.
 
-namespace acm2 {}  // namespace
+#endif  // WEBRTC_MEDIA_BASE_VIDEOSOURCEBASE_H_