Pepper: Make StartSelLdr asynchronous.

ppapi/native_client/src/trusted/plugin/sel_ldr_launcher_chrome.cc

 // 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.
 
 #include "native_client/src/include/nacl_macros.h"
+#include "ppapi/c/pp_errors.h"
+#include "ppapi/cpp/module.h"
 #include "ppapi/native_client/src/trusted/plugin/nacl_entry_points.h"
 #include "ppapi/native_client/src/trusted/plugin/sel_ldr_launcher_chrome.h"
 
-#include "ppapi/cpp/var.h"
-
 LaunchNaClProcessFunc launch_nacl_process = NULL;
 
 namespace plugin {
 
 bool SelLdrLauncherChrome::Start(const char* url) {
   NACL_NOTREACHED();
   return false;
 }
 
-bool SelLdrLauncherChrome::Start(PP_Instance instance,
+void SelLdrLauncherChrome::Start(PP_Instance instance,
                                  const char* url,
                                  bool uses_irt,
                                  bool uses_ppapi,
                                  bool enable_ppapi_dev,
                                  bool enable_dyncode_syscalls,
                                  bool enable_exception_handling,
                                  bool enable_crash_throttling,
-                                 nacl::string* error_message) {
-  *error_message = "";
-  if (!launch_nacl_process)
-    return false;
-  PP_Var var_error_message;
-  // send a synchronous message to the browser process
-  if (launch_nacl_process(instance,
-                          url,
-                          PP_FromBool(uses_irt),
-                          PP_FromBool(uses_ppapi),
-                          PP_FromBool(enable_ppapi_dev),
-                          PP_FromBool(enable_dyncode_syscalls),
-                          PP_FromBool(enable_exception_handling),
-                          PP_FromBool(enable_crash_throttling),
-                          &channel_,
-                          &var_error_message) != PP_EXTERNAL_PLUGIN_OK) {
-    pp::Var var_error_message_cpp(pp::PASS_REF, var_error_message);
-    if (var_error_message_cpp.is_string()) {
-      *error_message = var_error_message_cpp.AsString();
-    }
-    return false;
+                                 PP_Var* error_message,
+                                 pp::CompletionCallback callback) {
+  if (!launch_nacl_process) {
+    pp::Module::Get()->core()->CallOnMainThread(0, callback, PP_ERROR_FAILED);
+    return;
   }
-  return true;
+  launch_nacl_process(instance,
+                      url,
+                      PP_FromBool(uses_irt),
+                      PP_FromBool(uses_ppapi),
+                      PP_FromBool(enable_ppapi_dev),
+                      PP_FromBool(enable_dyncode_syscalls),
+                      PP_FromBool(enable_exception_handling),
+                      PP_FromBool(enable_crash_throttling),
+                      &channel_,
+                      error_message,
+                      callback.pp_completion_callback());
 }
 
 }  // namespace plugin