Shutdown cleanup

mojo/views/native_widget_view_manager.cc

 // 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.
 
 #include "mojo/views/native_widget_view_manager.h"
 
 #include "mojo/aura/window_tree_host_mojo.h"
 #include "mojo/services/public/cpp/input_events/input_events_type_converters.h"
 #include "mojo/services/public/cpp/view_manager/view.h"
 #include "ui/aura/client/aura_constants.h"
@@ skipping 73 matching lines @@
 
   DISALLOW_COPY_AND_ASSIGN(MinimalInputEventFilter);
 };
 
 }  // namespace
 
 NativeWidgetViewManager::NativeWidgetViewManager(
     views::internal::NativeWidgetDelegate* delegate, view_manager::Node* node)
     : NativeWidgetAura(delegate),
       node_(node) {
+  node_->AddObserver(this);
   node_->active_view()->AddObserver(this);
   window_tree_host_.reset(new WindowTreeHostMojo(node_, this));
   window_tree_host_->InitHost();
 
   ime_filter_.reset(
       new MinimalInputEventFilter(window_tree_host_->window()));
 
   focus_client_.reset(new wm::FocusController(new FocusRulesImpl));
 
   aura::client::SetFocusClient(window_tree_host_->window(),
                                focus_client_.get());
   aura::client::SetActivationClient(window_tree_host_->window(),
                                     focus_client_.get());
   window_tree_host_->window()->AddPreTargetHandler(focus_client_.get());
 
   aura::client::SetCaptureClient(
       window_tree_host_->window(),
       new aura::client::DefaultCaptureClient(window_tree_host_->window()));
 }
 
 NativeWidgetViewManager::~NativeWidgetViewManager() {
-  node_->active_view()->RemoveObserver(this);
+  if (node_->active_view())
+    node_->active_view()->RemoveObserver(this);
+  node_->RemoveObserver(this);
 }
 
 void NativeWidgetViewManager::InitNativeWidget(
     const views::Widget::InitParams& in_params) {
   views::Widget::InitParams params(in_params);
   params.parent = window_tree_host_->window();
   NativeWidgetAura::InitNativeWidget(params);
   capture_client_.reset(
       new wm::ScopedCaptureClient(window_tree_host_->window()));
 }
 
 void NativeWidgetViewManager::CompositorContentsChanged(
     const SkBitmap& bitmap) {
   node_->active_view()->SetContents(bitmap);
 }
 
+void NativeWidgetViewManager::OnNodeDestroyed(view_manager::Node* node) {
+  window_tree_host_.reset();
+}
+
+void NativeWidgetViewManager::OnNodeActiveViewChanged(
+    view_manager::Node* node,
+    view_manager::View* old_view,
+    view_manager::View* new_view) {
+  if (old_view)
+    old_view->RemoveObserver(this);
+  if (new_view)
+    new_view->AddObserver(this);
+}
+
 void NativeWidgetViewManager::OnViewInputEvent(view_manager::View* view,
                                                const EventPtr& event) {
   scoped_ptr<ui::Event> ui_event(event.To<scoped_ptr<ui::Event> >());
   if (ui_event.get())
     window_tree_host_->SendEventToProcessor(ui_event.get());
 }
 
 }  // namespace mojo