Add copyright headers DM.

Review URL: https://codereview.chromium.org/1037713003
diff --git a/dm/DMSrcSink.cpp b/dm/DMSrcSink.cpp
index fe31d61..06e1fe7 100644
--- a/dm/DMSrcSink.cpp
+++ b/dm/DMSrcSink.cpp
@@ -1,3 +1,10 @@
+/*
+ * Copyright 2015 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
 #include "DMSrcSink.h"
 #include "SamplePipeControllers.h"
 #include "SkCommonFlags.h"