Changes ownership of WindowTreeClient

content/renderer/mus/compositor_mus_connection.cc

 // Copyright 2015 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.
 
 #include "content/renderer/mus/compositor_mus_connection.h"
 
 #include "base/single_thread_task_runner.h"
 #include "content/renderer/input/input_handler_manager.h"
 #include "content/renderer/mus/render_widget_mus_connection.h"
 #include "ui/events/blink/blink_event_util.h"
@@ skipping 37 matching lines @@
 
 void CompositorMusConnection::AttachSurfaceOnMainThread(
     std::unique_ptr<ui::WindowSurfaceBinding> surface_binding) {
   DCHECK(main_task_runner_->BelongsToCurrentThread());
   compositor_task_runner_->PostTask(
       FROM_HERE,
       base::Bind(&CompositorMusConnection::AttachSurfaceOnCompositorThread,
                  this, base::Passed(std::move(surface_binding))));
 }
 
-CompositorMusConnection::~CompositorMusConnection() {}
+CompositorMusConnection::~CompositorMusConnection() {
+  base::AutoLock auto_lock(window_tree_client_lock_);
+  // Destruction must happen on the compositor task runner.
+  DCHECK(!window_tree_client_);
+}
 
 void CompositorMusConnection::AttachSurfaceOnCompositorThread(
     std::unique_ptr<ui::WindowSurfaceBinding> surface_binding) {
   DCHECK(compositor_task_runner_->BelongsToCurrentThread());
   window_surface_binding_ = std::move(surface_binding);
   if (root_) {
     root_->AttachSurface(ui::mojom::SurfaceType::DEFAULT,
                          std::move(window_surface_binding_));
   }
 }
 
 void CompositorMusConnection::CreateWindowTreeClientOnCompositorThread(
     mojo::InterfaceRequest<ui::mojom::WindowTreeClient> request) {
   DCHECK(compositor_task_runner_->BelongsToCurrentThread());
-  new ui::WindowTreeClient(this, nullptr, std::move(request));
+  DCHECK(!window_tree_client_);
+  std::unique_ptr<ui::WindowTreeClient> window_tree_client =
+      base::MakeUnique<ui::WindowTreeClient>(this, nullptr, std::move(request));
+  base::AutoLock auto_lock(window_tree_client_lock_);
+  window_tree_client_ = std::move(window_tree_client);
 }
 
 void CompositorMusConnection::OnConnectionLostOnMainThread() {
   DCHECK(main_task_runner_->BelongsToCurrentThread());
   RenderWidgetMusConnection* connection =
       RenderWidgetMusConnection::Get(routing_id_);
   if (!connection)
     return;
   connection->OnConnectionLost();
 }
@@ skipping 37 matching lines @@
         *event.AsMouseWheelEvent(), base::Bind(&GetScreenLocationFromEvent));
     return base::MakeUnique<blink::WebMouseWheelEvent>(blink_event);
   } else if (event.IsKeyEvent()) {
     blink::WebKeyboardEvent blink_event =
         ui::MakeWebKeyboardEvent(*event.AsKeyEvent());
     return base::MakeUnique<blink::WebKeyboardEvent>(blink_event);
   }
   return nullptr;
 }
 
-void CompositorMusConnection::OnDidDestroyClient(ui::WindowTreeClient* client) {
+void CompositorMusConnection::DeleteWindowTreeClient() {
   DCHECK(compositor_task_runner_->BelongsToCurrentThread());
+  std::unique_ptr<ui::WindowTreeClient> window_tree_client;
+  {
+    base::AutoLock auto_lock(window_tree_client_lock_);
+    window_tree_client = std::move(window_tree_client_);
+  }
   main_task_runner_->PostTask(
       FROM_HERE,
       base::Bind(&CompositorMusConnection::OnConnectionLostOnMainThread, this));
 }
 
 void CompositorMusConnection::OnEmbed(ui::Window* root) {
   DCHECK(compositor_task_runner_->BelongsToCurrentThread());
   root_ = root;
   root_->set_input_event_handler(this);
   if (window_surface_binding_) {
     root->AttachSurface(ui::mojom::SurfaceType::DEFAULT,
                         std::move(window_surface_binding_));
   }
 }
 
+void CompositorMusConnection::OnEmbedRootDestroyed(ui::Window* window) {
+  DeleteWindowTreeClient();
+}
+
+void CompositorMusConnection::OnLostConnection(ui::WindowTreeClient* client) {
+  DeleteWindowTreeClient();
+}
+
 void CompositorMusConnection::OnPointerEventObserved(
     const ui::PointerEvent& event,
     ui::Window* target) {
   // Compositor does not use StartPointerWatcher().
 }
 
 void CompositorMusConnection::OnWindowInputEvent(
     ui::Window* window,
     const ui::Event& event,
     std::unique_ptr<base::Callback<void(EventResult)>>* ack_callback) {
@@ skipping 21 matching lines @@
                    this, *ack_callback->get());
     ack_callback->reset();
   }
   main_task_runner_->PostTask(
       FROM_HERE,
       base::Bind(&CompositorMusConnection::OnWindowInputEventOnMainThread, this,
                  base::Passed(std::move(web_event)), ack));
 }
 
 }  // namespace content