Makes ash/wm/common a library

ash/wm/aura/wm_globals_aura.cc

 // Copyright 2016 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/aura/wm_globals_aura.h"
 
 #include "ash/display/window_tree_host_manager.h"
 #include "ash/session/session_state_delegate.h"
 #include "ash/shell.h"
 #include "ash/shell_delegate.h"
 #include "ash/wm/aura/wm_window_aura.h"
 #include "ash/wm/common/wm_activation_observer.h"
 #include "ash/wm/common/wm_display_observer.h"
 #include "ash/wm/common/wm_overview_mode_observer.h"
 #include "ash/wm/drag_window_resizer.h"
 #include "ash/wm/mru_window_tracker.h"
 #include "ash/wm/overview/window_selector_controller.h"
 #include "ash/wm/window_util.h"
 #include "base/memory/ptr_util.h"
 #include "ui/aura/client/focus_client.h"
 #include "ui/wm/public/activation_client.h"
 
 namespace ash {
 namespace wm {
-namespace {
-
-WmGlobalsAura* instance_ = nullptr;
-
-}  // namespace
-
-// static
-WmGlobals* WmGlobals::Get() {
-  return instance_;
-}
 
 WmGlobalsAura::WmGlobalsAura() {
-  DCHECK(!instance_);
-  instance_ = this;
+  WmGlobals::Set(this);
   Shell::GetInstance()->AddShellObserver(this);
 }
 
 WmGlobalsAura::~WmGlobalsAura() {
-  instance_ = nullptr;
+  WmGlobals::Set(nullptr);
   if (added_activation_observer_) {
     aura::client::GetActivationClient(Shell::GetPrimaryRootWindow())
         ->RemoveObserver(this);
   }
   if (added_display_observer_)
     Shell::GetInstance()->window_tree_host_manager()->RemoveObserver(this);
 
   Shell::GetInstance()->RemoveShellObserver(this);
 }
 
-// static
-WmGlobalsAura* WmGlobalsAura::Get() {
-  if (!instance_)
-    new WmGlobalsAura;
-  return instance_;
-}
-
 WmWindow* WmGlobalsAura::GetFocusedWindow() {
   return WmWindowAura::Get(
       aura::client::GetFocusClient(Shell::GetPrimaryRootWindow())
           ->GetFocusedWindow());
 }
 
 WmWindow* WmGlobalsAura::GetActiveWindow() {
   return WmWindowAura::Get(wm::GetActiveWindow());
 }
 
@@ skipping 114 matching lines @@
                     OnDisplayConfigurationChanged());
 }
 
 void WmGlobalsAura::OnOverviewModeEnded() {
   FOR_EACH_OBSERVER(WmOverviewModeObserver, overview_mode_observers_,
                     OnOverviewModeEnded());
 }
 
 }  // namespace wm
 }  // namespace ash