Revert of Move DefaultActivationClient to wm/core

ui/wm/core/default_activation_client.h

Index: ui/wm/core/default_activation_client.h
diff --git a/ui/wm/core/default_activation_client.h b/ui/wm/core/default_activation_client.h
deleted file mode 100644
index 3b6bffc319616a79006fdf66e1c0438291f41ad3..0000000000000000000000000000000000000000
--- a/ui/wm/core/default_activation_client.h
+++ /dev/null
@@ -1,73 +0,0 @@
-// Copyright 2013 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 UI_WM_CORE_DEFAULT_ACTIVATION_CLIENT_H_
-#define UI_WM_CORE_DEFAULT_ACTIVATION_CLIENT_H_
-
-#include <vector>
-
-#include "base/compiler_specific.h"
-#include "base/logging.h"
-#include "base/observer_list.h"
-#include "ui/aura/window_observer.h"
-#include "ui/wm/public/activation_client.h"
-#include "ui/wm/wm_export.h"
-
-namespace aura {
-namespace client {
-class ActivationChangeObserver;
-}
-}
-
-namespace wm {
-
-// Simple ActivationClient implementation for use by tests and other targets
-// that just need basic behavior (e.g. activate windows whenever requested,
-// restack windows at the top when they're activated, etc.). This object deletes
-// itself when the root window it is associated with is destroyed.
-class WM_EXPORT DefaultActivationClient : public aura::client::ActivationClient,
-                                          public aura::WindowObserver {
- public:
-  explicit DefaultActivationClient(aura::Window* root_window);
-
-  // Overridden from aura::client::ActivationClient:
-  virtual void AddObserver(
-      aura::client::ActivationChangeObserver* observer) OVERRIDE;
-  virtual void RemoveObserver(
-      aura::client::ActivationChangeObserver* observer) OVERRIDE;
-  virtual void ActivateWindow(aura::Window* window) OVERRIDE;
-  virtual void DeactivateWindow(aura::Window* window) OVERRIDE;
-  virtual aura::Window* GetActiveWindow() OVERRIDE;
-  virtual aura::Window* GetActivatableWindow(aura::Window* window) OVERRIDE;
-  virtual aura::Window* GetToplevelWindow(aura::Window* window) OVERRIDE;
-  virtual bool OnWillFocusWindow(aura::Window* window,
-                                 const ui::Event* event) OVERRIDE;
-  virtual bool CanActivateWindow(aura::Window* window) const OVERRIDE;
-
-  // Overridden from WindowObserver:
-  virtual void OnWindowDestroyed(aura::Window* window) OVERRIDE;
-
- private:
-  class Deleter;
-
-  virtual ~DefaultActivationClient();
-  void RemoveActiveWindow(aura::Window* window);
-
-  // This class explicitly does NOT store the active window in a window property
-  // to make sure that ActivationChangeObserver is not treated as part of the
-  // aura API. Assumptions to that end will cause tests that use this client to
-  // fail.
-  std::vector<aura::Window*> active_windows_;
-
-  // The window which was active before the currently active one.
-  aura::Window* last_active_;
-
-  ObserverList<aura::client::ActivationChangeObserver> observers_;
-
-  DISALLOW_COPY_AND_ASSIGN(DefaultActivationClient);
-};
-
-}  // namespace wm
-
-#endif  // UI_WM_CORE_DEFAULT_ACTIVATION_CLIENT_H_