Change ppapi C++ comment style into C.

ppapi/c/dev/ppb_audio_trusted_dev.h

-// 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_
 
 #include "ppapi/c/pp_completion_callback.h"
 #include "ppapi/c/pp_instance.h"
 #include "ppapi/c/pp_resource.h"
 
 #define PPB_AUDIO_TRUSTED_DEV_INTERFACE "PPB_AudioTrusted(Dev);0.3"
 
 /**
@@ skipping 24 matching lines @@
 
   /**
    * Get the shared memory interface.  Use once Open has completed.
    * Returns PP_OK on success.
    */
   int32_t (*GetSharedMemory)(PP_Resource audio,
                              int* shm_handle,
                              uint32_t* shm_size);
 };
 
-#endif  // PPAPI_C_DEV_PPB_AUDIO_TRUSTED_DEV_H_
+#endif  /* PPAPI_C_DEV_PPB_AUDIO_TRUSTED_DEV_H_ */
+