Move the concept of Activation to the Shell.

ui/aura/test/test_activation_client.h

+// Copyright (c) 2011 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_AURA_TEST_TEST_ACTIVATION_CLIENT_H_
+#define UI_AURA_TEST_TEST_ACTIVATION_CLIENT_H_
+#pragma once
+
+#include "base/compiler_specific.h"
+#include "base/logging.h"
+#include "ui/aura/client/activation_client.h"
+#include "ui/aura/window_observer.h"
+
+namespace aura {
+namespace test {
+
+class TestActivationClient : public ActivationClient, public WindowObserver {
+ public:
+  TestActivationClient();
+  virtual ~TestActivationClient();
+
+  // Overridden from ActivationClient:
+  virtual void ActivateWindow(Window* window) OVERRIDE;
+  virtual void DeactivateWindow(Window* window) OVERRIDE;
+  virtual Window* GetActiveWindow() OVERRIDE;
+  virtual bool CanFocusWindow(Window* window) const OVERRIDE;
+
+  // Overridden from WindowObserver:
+  virtual void OnWindowDestroyed(Window* window) OVERRIDE;
+
+ private:
+  // This class explicitly does NOT store the active window in a window property
+  // to make sure that storing the active window in a property is not treated as
+  // part of the aura API. Assumptions to that end will cause tests that use
+  // this client to fail.
+  Window* active_window_;
+
+  DISALLOW_COPY_AND_ASSIGN(TestActivationClient);
+};
+
+}  // namespace test
+}  // namespace aura
+
+#endif  // UI_AURA_TEST_TEST_ACTIVATION_CLIENT_H_