Change ppapi C++ comment style into C.

ppapi/c/dev/ppb_file_io_trusted_dev.h

Index: ppapi/c/dev/ppb_file_io_trusted_dev.h
diff --git a/ppapi/c/dev/ppb_file_io_trusted_dev.h b/ppapi/c/dev/ppb_file_io_trusted_dev.h
index ef6715b38cdf9e0cd2209ca953d00a88a82453c9..e7b677fe2d810c71e244731789c06582e76dadb9 100644
--- a/ppapi/c/dev/ppb_file_io_trusted_dev.h
+++ b/ppapi/c/dev/ppb_file_io_trusted_dev.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_DEV_PPB_FILE_IO_TRUSTED_DEV_H_
 #define PPAPI_C_DEV_PPB_FILE_IO_TRUSTED_DEV_H_
 
@@ -42,4 +42,5 @@ struct PPB_FileIOTrusted_Dev {
   // undesirable.
 };
 
-#endif  // PPAPI_C_DEV_PPB_FILE_IO_TRUSTED_DEV_H_
+#endif  /* PPAPI_C_DEV_PPB_FILE_IO_TRUSTED_DEV_H_ */
+