mojo: terminate apps if the shell goes away

mojo/public/cpp/application/application_impl.h

Index: mojo/public/cpp/application/application_impl.h
diff --git a/mojo/public/cpp/application/application_impl.h b/mojo/public/cpp/application/application_impl.h
index 37a95fb6c6a12bbe89c3525a8188967db8fa8b6a..2a1a5969bfad2995f781bf5a980237182b4e4032 100644
--- a/mojo/public/cpp/application/application_impl.h
+++ b/mojo/public/cpp/application/application_impl.h
@@ -59,7 +59,7 @@ class ApplicationDelegate;
 //   BarImpl(ApplicationContext* app_context, BarContext* service_context)
 //          : app_context_(app_context), servicecontext_(context) {}
 //
-// Create an ApplicationDele instance that collects any service implementations.
+// Create an ApplicationImpl instance that collects any service implementations.
 //
 // ApplicationImpl app(service_provider_handle);
 // app.AddService<FooImpl>();
@@ -89,10 +89,25 @@ class ApplicationImpl : public InterfaceImpl<Application> {
   }
 
  private:
+  class ShellPtrWatcher : public ErrorHandler {
+   public:
+    explicit ShellPtrWatcher(ApplicationImpl* impl);
+    virtual ~ShellPtrWatcher();
+    virtual void OnConnectionError() MOJO_OVERRIDE;
+   private:
+    ApplicationImpl* impl_;
+    MOJO_DISALLOW_COPY_AND_ASSIGN(ShellPtrWatcher);
+  };
+
   friend MojoResult (::MojoMain)(MojoHandle);
 
   void BindShell(ScopedMessagePipeHandle shell_handle);
   void BindShell(MojoHandle shell_handle);
+  void ClearConnections();
+  void OnShellError() { ClearConnections(); Terminate(); };
+
+  // Quits the main run loop for this application.
+  void Terminate();
 
   // Application implementation.
   virtual void AcceptConnection(const String& requestor_url,
@@ -103,6 +118,7 @@ class ApplicationImpl : public InterfaceImpl<Application> {
   ServiceRegistryList outgoing_service_registries_;
   ApplicationDelegate* delegate_;
   ShellPtr shell_;
+  ShellPtrWatcher shell_watch_;
 
   MOJO_DISALLOW_COPY_AND_ASSIGN(ApplicationImpl);
 };