Pepper: Move DoPostMessage out of trusted plugin.

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 422 matching lines @@
                              [out] PP_Var full_url,
                              [out] PP_PNaClOptions pnacl_options);
 
   /* Returns the filenames for the llc and ld tools, parsing that information
    * from the file given in |filename|.
    */
   PP_Bool GetPnaclResourceInfo([in] PP_Instance instance,
                                [in] str_t filename,
                                [out] PP_Var llc_tool_name,
                                [out] PP_Var ld_tool_name);
+
+  /* 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);

[bbudge, 2014/05/06 20:48:20]

Are you using str_t here to make usage simpler? In the implementation you have
to convert this back into a PP_Var to send over the MessageChannel. I guess this
is the logical choice unless other call sites would already have constructed a
PP_Var. I only see a single call, in service_runtime.cc.

 };