Create a RegisterViewAssociate method in ViewManager

services/ui/launcher/launch_instance.h

Index: services/ui/launcher/launch_instance.h
diff --git a/services/ui/launcher/launch_instance.h b/services/ui/launcher/launch_instance.h
index 644f31dbb817a44cc35e0c8f5f037bbbdb9eeb69..c4510e9be120c771d6742b88f9e89f27d0251f04 100644
--- a/services/ui/launcher/launch_instance.h
+++ b/services/ui/launcher/launch_instance.h
@@ -20,7 +20,8 @@ namespace launcher {
 
 class LauncherViewTree;
 
-class LaunchInstance : public mojo::NativeViewportEventDispatcher {
+class LaunchInstance : public mojo::NativeViewportEventDispatcher,
+                       public mojo::ui::ViewAssociateWatcher {
  public:
   LaunchInstance(mojo::ApplicationImpl* app_impl,
                  const std::string& app_url,
@@ -29,6 +30,11 @@ class LaunchInstance : public mojo::NativeViewportEventDispatcher {
 
   void Launch();
 
+  // |ViewAssociateWatcher|
+  void OnViewAssociateConnectionError(
+      const mojo::String& label,
+      const OnViewAssociateConnectionErrorCallback& callback) override;
+
  private:
   // |NativeViewportEventDispatcher|:
   void OnEvent(mojo::EventPtr event,