Move even more from WmShell to Shell

ash/common/system/chromeos/brightness/tray_brightness.cc

 // 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.
 
 #include "ash/common/system/chromeos/brightness/tray_brightness.h"
 
 #include <algorithm>
 
 #include "ash/common/material_design/material_design_controller.h"
 #include "ash/common/shell_observer.h"
@@ skipping 102 matching lines @@
   tri_view->AddView(TriView::Container::START, icon);
 
   slider_ = TrayPopupUtils::CreateSlider(this);
   slider_->SetValue(static_cast<float>(initial_percent / 100.0));
   slider_->SetAccessibleName(
       rb.GetLocalizedString(IDS_ASH_STATUS_TRAY_BRIGHTNESS));
   tri_view->AddView(TriView::Container::CENTER, slider_);
 
   if (is_default_view_) {
     Shell::GetInstance()->AddShellObserver(this);
-    SetVisible(WmShell::Get()
+    SetVisible(Shell::Get()
                    ->maximize_mode_controller()
                    ->IsMaximizeModeWindowManagerEnabled());
   } else {
     tri_view->SetContainerVisible(TriView::Container::END, false);
   }
 }
 
 BrightnessView::~BrightnessView() {
   if (is_default_view_)
     Shell::GetInstance()->RemoveShellObserver(this);
@@ skipping 141 matching lines @@
   if (!display::Display::HasInternalDisplay())
     return;
 
   if (brightness_view_ && brightness_view_->visible())
     SetDetailedViewCloseDelay(kTrayPopupAutoCloseDelayInSeconds);
   else
     PopupDetailedView(kTrayPopupAutoCloseDelayInSeconds, false);
 }
 
 }  // namespace ash