Ensure that in Desktop AURA the WindowModalityController class is at the head of the event pre targ…

ui/views/corewm/window_modality_controller.cc

 // Copyright (c) 2012 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 "ui/views/corewm/window_modality_controller.h"
 
 #include <algorithm>
 
 #include "ui/aura/client/aura_constants.h"
 #include "ui/aura/client/capture_client.h"
 #include "ui/aura/env.h"
 #include "ui/aura/root_window.h"
 #include "ui/aura/window.h"
 #include "ui/aura/window_property.h"
 #include "ui/base/ui_base_types.h"
 #include "ui/events/event.h"
+#include "ui/events/event_target.h"
 #include "ui/views/corewm/window_animations.h"
 #include "ui/views/corewm/window_util.h"
 
 namespace views {
 namespace corewm {
 
 // Transient child's modal parent.
 extern const aura::WindowProperty<aura::Window*>* const kModalParentKey;
 DEFINE_WINDOW_PROPERTY_KEY(aura::Window*, kModalParentKey, NULL);
 
@@ skipping 61 matching lines @@
   aura::Window* toplevel = GetToplevelWindow(window);
   if (!toplevel)
     return NULL;
 
   return GetModalTransientChild(toplevel, window);
 }
 
 ////////////////////////////////////////////////////////////////////////////////
 // WindowModalityController, public:
 
-WindowModalityController::WindowModalityController() {
+WindowModalityController::WindowModalityController(
+    ui::EventTarget* event_target)
+    : event_target_(event_target) {
   aura::Env::GetInstance()->AddObserver(this);
+  DCHECK(event_target->IsPreTargetListEmpty());
+  event_target_->AddPreTargetHandler(this);
 }
 
 WindowModalityController::~WindowModalityController() {
+  event_target_->RemovePreTargetHandler(this);
   aura::Env::GetInstance()->RemoveObserver(this);
   for (size_t i = 0; i < windows_.size(); ++i)
     windows_[i]->RemoveObserver(this);
 }
 
 ////////////////////////////////////////////////////////////////////////////////
 // WindowModalityController, aura::EventFilter implementation:
 
 void WindowModalityController::OnKeyEvent(ui::KeyEvent* event) {
   aura::Window* target = static_cast<aura::Window*>(event->target());
@@ skipping 59 matching lines @@
   aura::Window* modal_transient_child = GetModalTransient(target);
   if (modal_transient_child && (event->type() == ui::ET_MOUSE_PRESSED ||
                                 event->type() == ui::ET_TOUCH_PRESSED)) {
     AnimateWindow(modal_transient_child, WINDOW_ANIMATION_TYPE_BOUNCE);
   }
   return !!modal_transient_child;
 }
 
 }  // namespace corewm
 }  // namespace views