Change ppapi C++ comment style into C.

ppapi/c/dev/ppb_audio_trusted_dev.h

Index: ppapi/c/dev/ppb_audio_trusted_dev.h
diff --git a/ppapi/c/dev/ppb_audio_trusted_dev.h b/ppapi/c/dev/ppb_audio_trusted_dev.h
index 0bada3640bef1cd4169e00794e651419685a7349..0c1ff3b6627613670c2fa96d7c779a6f0f1587b7 100644
--- a/ppapi/c/dev/ppb_audio_trusted_dev.h
+++ b/ppapi/c/dev/ppb_audio_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_AUDIO_TRUSTED_DEV_H_
 #define PPAPI_C_DEV_PPB_AUDIO_TRUSTED_DEV_H_
 
@@ -46,4 +46,5 @@ struct PPB_AudioTrusted_Dev {
                              uint32_t* shm_size);
 };
 
-#endif  // PPAPI_C_DEV_PPB_AUDIO_TRUSTED_DEV_H_
+#endif  /* PPAPI_C_DEV_PPB_AUDIO_TRUSTED_DEV_H_ */
+