Separated alt-tab window cycle from overview mode

ash/wm/window_cycle_list.h

Index: ash/wm/window_cycle_list.h
diff --git a/ash/wm/window_cycle_list.h b/ash/wm/window_cycle_list.h
new file mode 100644
index 0000000000000000000000000000000000000000..7efddbb9fb618602d253813ff71aab6194325f74
--- /dev/null
+++ b/ash/wm/window_cycle_list.h
@@ -0,0 +1,61 @@
+// 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.
+
+#ifndef ASH_WM_WINDOW_CYCLE_LIST_H_
+#define ASH_WM_WINDOW_CYCLE_LIST_H_
+
+#include <vector>
+
+#include "ash/ash_export.h"
+#include "ash/wm/window_cycle_controller.h"
+#include "base/basictypes.h"
+#include "base/compiler_specific.h"
+#include "base/memory/scoped_ptr.h"
+#include "ui/aura/window_observer.h"
+
+namespace ash {
+
+class ScopedShowWindow;
+
+// Tracks a set of Windows that can be stepped through. This class is used by
+// the WindowCycleController.
+class ASH_EXPORT WindowCycleList : public aura::WindowObserver {
+ public:
+  typedef std::vector<aura::Window*> WindowList;
+
+  explicit WindowCycleList(const WindowList& windows);
+  virtual ~WindowCycleList();
+
+  bool empty() const { return windows_.empty(); }
+
+  // Cycles to the next or previous window based on |direction|.
+  void Step(WindowCycleController::Direction direction);
+
+  const WindowList& windows() const { return windows_; }
+
+ private:
+  // aura::WindowObserver overrides:
+  // There is a chance a window is destroyed, for example by JS code. We need to
+  // take care of that even if it is not intended for the user to close a window
+  // while window cycling.
+  virtual void OnWindowDestroyed(aura::Window* window) OVERRIDE;
+
+  // List of weak pointers to windows to use while cycling with the keyboard.
+  // List is built when the user initiates the gesture (i.e. hits alt-tab the
+  // first time) and is emptied when the gesture is complete (i.e. releases the
+  // alt key).
+  WindowList windows_;
+
+  // Current position in the |windows_|
+  int current_index_;
+
+  // Wrapper for the window brought to the front.
+  scoped_ptr<ScopedShowWindow> showing_window_;
+
+  DISALLOW_COPY_AND_ASSIGN(WindowCycleList);
+};
+
+}  // namespace ash
+
+#endif  // ASH_WM_WINDOW_CYCLE_LIST_H_