Moves maintaining ShellObservers back 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"
 #include "ash/common/system/brightness_control_delegate.h"
 #include "ash/common/system/tray/tray_constants.h"
 #include "ash/common/system/tray/tray_popup_utils.h"
 #include "ash/common/system/tray/tri_view.h"
 #include "ash/common/wm/maximize_mode/maximize_mode_controller.h"
 #include "ash/common/wm_shell.h"
 #include "ash/resources/grit/ash_resources.h"
 #include "ash/resources/vector_icons/vector_icons.h"
+#include "ash/shell.h"
 #include "ash/strings/grit/ash_strings.h"
 #include "base/bind.h"
 #include "base/strings/utf_string_conversions.h"
 #include "base/threading/thread_task_runner_handle.h"
 #include "chromeos/dbus/dbus_thread_manager.h"
 #include "chromeos/dbus/power_manager_client.h"
 #include "ui/base/resource/resource_bundle.h"
 #include "ui/display/display.h"
 #include "ui/gfx/image/image.h"
 #include "ui/gfx/paint_vector_icon.h"
@@ skipping 82 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_) {
-    WmShell::Get()->AddShellObserver(this);
+    Shell::GetInstance()->AddShellObserver(this);
     SetVisible(WmShell::Get()
                    ->maximize_mode_controller()
                    ->IsMaximizeModeWindowManagerEnabled());
   } else {
     tri_view->SetContainerVisible(TriView::Container::END, false);
   }
 }
 
 BrightnessView::~BrightnessView() {
   if (is_default_view_)
-    WmShell::Get()->RemoveShellObserver(this);
+    Shell::GetInstance()->RemoveShellObserver(this);
 }
 
 void BrightnessView::SetBrightnessPercent(double percent) {
   last_percent_ = percent;
   if (!dragging_)
     slider_->SetValue(static_cast<float>(percent / 100.0));
 }
 
 void BrightnessView::OnMaximizeModeStarted() {
   SetVisible(true);
@@ skipping 131 matching lines @@
   if (!display::Display::HasInternalDisplay())
     return;
 
   if (brightness_view_ && brightness_view_->visible())
     SetDetailedViewCloseDelay(kTrayPopupAutoCloseDelayInSeconds);
   else
     PopupDetailedView(kTrayPopupAutoCloseDelayInSeconds, false);
 }
 
 }  // namespace ash