Pass error messages from native messaging to web-app.

remoting/host/setup/daemon_controller_delegate_mac.h

Index: remoting/host/setup/daemon_controller_delegate_mac.h
diff --git a/remoting/host/setup/daemon_controller_delegate_mac.h b/remoting/host/setup/daemon_controller_delegate_mac.h
index e6c4a4c82eb933f85d82714e934e2182ec39041a..0af67f1d5d95cee963ff61a2d297b7fc7359d86f 100644
--- a/remoting/host/setup/daemon_controller_delegate_mac.h
+++ b/remoting/host/setup/daemon_controller_delegate_mac.h
@@ -22,28 +22,36 @@ class DaemonControllerDelegateMac : public DaemonController::Delegate {
   void SetConfigAndStart(
       scoped_ptr<base::DictionaryValue> config,
       bool consent,
-      const DaemonController::CompletionCallback& done) override;
+      const base::Closure& on_done,
+      const DaemonController::ErrorCallback& on_error) override;
   void UpdateConfig(scoped_ptr<base::DictionaryValue> config,
-                    const DaemonController::CompletionCallback& done) override;
-  void Stop(const DaemonController::CompletionCallback& done) override;
+                    const base::Closure& on_done,
+                    const DaemonController::ErrorCallback& on_error) override;
+  void Stop(const base::Closure& on_done,
+            const DaemonController::ErrorCallback& on_error) override;
   DaemonController::UsageStatsConsent GetUsageStatsConsent() override;
 
  private:
   void ShowPreferencePane(const std::string& config_data,
-                          const DaemonController::CompletionCallback& done);
+                          const base::Closure& on_done,
+                          const DaemonController::ErrorCallback& on_error);
   void RegisterForPreferencePaneNotifications(
-      const DaemonController::CompletionCallback &done);
+      const base::Closure& on_done,
+      const DaemonController::ErrorCallback& on_error);
   void DeregisterForPreferencePaneNotifications();
   void PreferencePaneCallbackDelegate(CFStringRef name);
 
-  static bool DoShowPreferencePane(const std::string& config_data);
+  static bool DoShowPreferencePane(
+      const std::string& config_data,
+      const DaemonController::ErrorCallback& on_error);
   static void PreferencePaneCallback(CFNotificationCenterRef center,
                                      void* observer,
                                      CFStringRef name,
                                      const void* object,
                                      CFDictionaryRef user_info);
 
-  DaemonController::CompletionCallback current_callback_;
+  base::Closure on_done_;
+  DaemonController::ErrorCallback on_error_;
 
   DISALLOW_COPY_AND_ASSIGN(DaemonControllerDelegateMac);
 };