Changes ownership of WindowTreeClient

services/ui/public/cpp/window_tree_client_delegate.h

 // Copyright 2014 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.
 
 #ifndef SERVICES_UI_PUBLIC_CPP_WINDOW_TREE_CLIENT_DELEGATE_H_
 #define SERVICES_UI_PUBLIC_CPP_WINDOW_TREE_CLIENT_DELEGATE_H_
 
 #include <string>
 
 #include "services/shell/public/interfaces/interface_provider.mojom.h"
@@ skipping 11 matching lines @@
 // Interface implemented by an application using mus.
 class WindowTreeClientDelegate {
  public:
   // Called when the application implementing this interface is embedded at
   // |root|.
   // NOTE: this is only invoked if the WindowTreeClient is created with an
   // InterfaceRequest.
   virtual void OnEmbed(Window* root) = 0;
 
   // Sent when another app is embedded in |root| (one of the roots of the
-  // connection). Afer this call |root| is deleted. If |root| is the only root
-  // and the connection is configured to delete when there are no roots (the
-  // default), then after |root| is destroyed the connection is destroyed as
-  // well.
+  // connection). Afer this call |root| is deleted. If the associated
+  // WindowTreeClient was created from a WindowTreeClientRequest then
+  // OnEmbedRootDestroyed() is called after the window is deleted.
   virtual void OnUnembed(Window* root);
 
-  // Called from the destructor of WindowTreeClient after all the Windows have
-  // been destroyed. |client| is no longer valid after this call.
-  virtual void OnDidDestroyClient(WindowTreeClient* client) = 0;
+  // Called when the embed root has been destroyed on the server side (or
+  // another client was embedded in the same window). This is only called if the
+  // WindowTreeClient was created from an InterfaceRequest. Generally when this
+  // is called the delegate should delete the WindowTreeClient.
+  virtual void OnEmbedRootDestroyed(Window* root) = 0;
+
+  // Called when the connection to the window server has been lost. After this
+  // call the windows are still valid, and you can still do things, but they
+  // have no real effect. Generally when this is called clients should delete
+  // the corresponding WindowTreeClient.
+  virtual void OnLostConnection(WindowTreeClient* client) = 0;
 
   // Called when the WindowTreeClient receives an input event observed via
   // StartPointerWatcher(). |target| may be null for events that were sent to
   // windows owned by other processes.
   virtual void OnPointerEventObserved(const ui::PointerEvent& event,
                                       Window* target) = 0;
 
  protected:
   virtual ~WindowTreeClientDelegate() {}
 };
 
 }  // namespace ui
 
 #endif  // SERVICES_UI_PUBLIC_CPP_WINDOW_TREE_CLIENT_DELEGATE_H_