Move even more from WmShell to Shell

ash/wm/ash_focus_rules.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/ash_focus_rules.h"
 
 #include "ash/common/wm/container_finder.h"
 #include "ash/common/wm/focus_rules.h"
 #include "ash/common/wm/mru_window_tracker.h"
 #include "ash/common/wm/window_state.h"
@@ skipping 62 matching lines @@
   return true;
 }
 
 aura::Window* AshFocusRules::GetNextActivatableWindow(
     aura::Window* ignore) const {
   DCHECK(ignore);
 
   // Start from the container of the most-recently-used window. If the list of
   // MRU windows is empty, then start from the container of the window that just
   // lost focus |ignore|.
-  MruWindowTracker* mru = WmShell::Get()->mru_window_tracker();
+  MruWindowTracker* mru = Shell::Get()->mru_window_tracker();
   std::vector<WmWindow*> windows = mru->BuildMruWindowList();
   aura::Window* starting_window =
       windows.empty() ? ignore : WmWindow::GetAuraWindow(windows[0]);
 
   // Look for windows to focus in |starting_window|'s container. If none are
   // found, we look in all the containers in front of |starting_window|'s
   // container, then all behind.
   int starting_container_index = 0;
   aura::Window* root = starting_window->GetRootWindow();
   if (!root)
@@ skipping 45 matching lines @@
     WindowState* window_state = GetWindowState(*i);
     if (*i != ignore && window_state->CanActivate() &&
         !window_state->IsMinimized())
       return *i;
   }
   return NULL;
 }
 
 }  // namespace wm
 }  // namespace ash