Change ppapi C++ comment style into C.

ppapi/c/dev/ppp_class_deprecated.h

Index: ppapi/c/dev/ppp_class_deprecated.h
diff --git a/ppapi/c/dev/ppp_class_deprecated.h b/ppapi/c/dev/ppp_class_deprecated.h
index 2f82348c78a3d37e7b84562c3cd85871c131a476..0f39d26430ce41c4565fc9f869e95e1513427244 100644
--- a/ppapi/c/dev/ppp_class_deprecated.h
+++ b/ppapi/c/dev/ppp_class_deprecated.h
@@ -1,7 +1,7 @@
-// Copyright (c) 2010 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.
-
+/* Copyright (c) 2010 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 PPAPI_C_PPP_CLASS_DEPRECATED_H_
 #define PPAPI_C_PPP_CLASS_DEPRECATED_H_
 
@@ -131,4 +131,5 @@ struct PPP_Class_Deprecated {
  * @}
  * End addtogroup PPP
  */
-#endif  // PPAPI_C_PPP_CLASS_DEPRECATED_H_
+#endif  /* PPAPI_C_PPP_CLASS_DEPRECATED_H_ */
+