Drop NaCl support for posting stdout/stderr to JS.

ppapi/api/private/ppb_nacl_private.idl

 /* Copyright (c) 2012 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.
  */
 
 /* This file contains NaCl private interfaces. This interface is not versioned
  * and is for internal Chrome use. It may change without notice. */
 
 label Chrome {
   M25 = 1.0
@@ skipping 326 matching lines @@
   PP_Bool GetPnaclResourceInfo([in] PP_Instance instance,
                                [out] PP_Var llc_tool_name,
                                [out] PP_Var ld_tool_name);
 
   // PP_Var string of attributes describing the CPU features supported
   // by the current architecture. The string is a comma-delimited list
   // of attributes supported by LLVM in its -mattr= option:
   //   http://llvm.org/docs/CommandGuide/llc.html#cmdoption-mattr
   PP_Var GetCpuFeatureAttrs();
 
-  /* Posts a message to the JavaScript object for the given instance.
-   * This method may be called on any thread.
-   */
-  void PostMessageToJavaScript([in] PP_Instance instance,
-                               [in] str_t message);
-
   /* Downloads the .nexe file at the given URL to a file, and sets |file_info|
    * to information for a handle to a file containing its contents.
    * If metadata for identity-based validation caching is available
    * then it sets token information in |file_info| (otherwise left untouched).
    */
   void DownloadNexe([in] PP_Instance instance,
                     [in] str_t url,
                     [out] PP_NaClFileInfo file_info,
                     [in] PP_CompletionCallback callback);
 
@@ skipping 34 matching lines @@
    * Otherwise, |stream_callback| is called repeatedly with blocks of data
    * as they are received. |stream_finished_callback| is called after all
    * data has been received and dispatched to |stream_callback|.
    */
   void StreamPexe([in] PP_Instance instance,
                   [in] str_t pexe_url,
                   [in] int32_t opt_level,
                   [in] PPP_PexeStreamHandler stream_handler,
                   [inout] mem_t stream_handler_user_data);
 };