Show more different NaCl loading errors.

ppapi/native_client/src/trusted/plugin/service_runtime.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.
  */
 
 #define NACL_LOG_MODULE_NAME "Plugin::ServiceRuntime"
 
 #include "native_client/src/trusted/plugin/service_runtime.h"
 
@@ skipping 709 matching lines @@
 
   nacl::scoped_ptr<SelLdrLauncherChrome>
       tmp_subprocess(new SelLdrLauncherChrome());
   if (NULL == tmp_subprocess.get()) {
     NaClLog(LOG_ERROR, "ServiceRuntime::Start (subprocess create failed)\n");
     params.error_info->SetReport(
         ERROR_SEL_LDR_CREATE_LAUNCHER,
         "ServiceRuntime: failed to create sel_ldr launcher");
     return false;
   }
+  nacl::string error_message;
   bool started = tmp_subprocess->Start(plugin_->pp_instance(),
                                        params.url.c_str(),
                                        params.uses_irt,
                                        params.uses_ppapi,
                                        params.enable_dev_interfaces,
                                        params.enable_dyncode_syscalls,
-                                       params.enable_exception_handling);
+                                       params.enable_exception_handling,
+                                       &error_message);
   if (!started) {
     NaClLog(LOG_ERROR, "ServiceRuntime::Start (start failed)\n");
-    params.error_info->SetReport(ERROR_SEL_LDR_LAUNCH,
-                                 "ServiceRuntime: failed to start");
+    if (error_message.empty()) {
+      params.error_info->SetReport(ERROR_SEL_LDR_LAUNCH,
+                                   "ServiceRuntime: failed to start");
+    } else {
+      params.error_info->SetReport(ERROR_SEL_LDR_LAUNCH,
+                                   "ServiceRuntime: failed to start",
+                                   error_message);
+    }
     return false;
   }
 
   subprocess_.reset(tmp_subprocess.release());
   NaClLog(4, "ServiceRuntime::StartSelLdr (return 1)\n");
   return true;
 }
 
 void ServiceRuntime::WaitForSelLdrStart() {
   nacl::MutexLocker take(&mu_);
@@ skipping 119 matching lines @@
 
 nacl::string ServiceRuntime::GetCrashLogOutput() {
   if (NULL != subprocess_.get()) {
     return subprocess_->GetCrashLogOutput();
   } else {
     return std::string();
   }
 }
 
 }  // namespace plugin