Change ppapi C++ comment style into C.

ppapi/c/dev/ppb_font_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_FONT_DEV_H_
 #define PPAPI_C_DEV_PPB_FONT_DEV_H_
 
 #include "ppapi/c/pp_bool.h"
 #include "ppapi/c/pp_macros.h"
 #include "ppapi/c/pp_module.h"
 #include "ppapi/c/pp_resource.h"
 #include "ppapi/c/pp_stdint.h"
 #include "ppapi/c/pp_var.h"
 
@@ skipping 151 matching lines @@
                                       int32_t pixel_position);
 
   // Returns the horizontal advance to the given character if the string was
   // placed at the given position. This handles complex scripts such as Arabic,
   // where characters may be combined or replaced depending on context.
   int32_t (*PixelOffsetForCharacter)(PP_Resource font,
                                      const struct PP_TextRun_Dev* text,
                                      uint32_t char_offset);
 };
 
-#endif  // PPAPI_C_DEV_PPB_FONT_DEV_H_
+#endif  /* PPAPI_C_DEV_PPB_FONT_DEV_H_ */
+