Refactor most recently used window tracking into a separate class.

ash/wm/window_cycle_list.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 "ash/wm/window_cycle_list.h"
 
+#include "ash/shell.h"
+#include "ash/wm/mru_window_tracker.h"
 #include "ash/wm/window_util.h"
 #include "ui/aura/window.h"
 #include "ui/views/corewm/window_animations.h"
 
 namespace ash {
 
 WindowCycleList::WindowCycleList(const WindowList& windows)
     : windows_(windows),
       current_index_(-1) {
+  ash::Shell::GetInstance()->mru_window_tracker()->IgnoreActivations(true);
   // Locate the currently active window in the list to use as our start point.
   aura::Window* active_window = wm::GetActiveWindow();
 
   // The active window may not be in the cycle list, which is expected if there
   // are additional modal windows on the screen.
   current_index_ = GetWindowIndex(active_window);
 
   for (WindowList::const_iterator i = windows_.begin(); i != windows_.end();
        ++i) {
     (*i)->AddObserver(this);
   }
 }
 
 WindowCycleList::~WindowCycleList() {
+  ash::Shell::GetInstance()->mru_window_tracker()->IgnoreActivations(false);
   for (WindowList::const_iterator i = windows_.begin(); i != windows_.end();
        ++i) {
     (*i)->RemoveObserver(this);
   }
 }
 
 void WindowCycleList::Step(Direction direction) {
   if (windows_.empty())
     return;
 
@@ skipping 34 matching lines @@
   DCHECK(i != windows_.end());
   int removed_index = static_cast<int>(i - windows_.begin());
   windows_.erase(i);
   if (current_index_ > removed_index)
     current_index_--;
   else if (current_index_ == static_cast<int>(windows_.size()))
     current_index_--;
 }
 
 }  // namespace ash