Move full-screen detection logic from PanelManager to DisplaySettingsProvider.

chrome/browser/ui/panels/display_settings_provider_win.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 "chrome/browser/ui/panels/display_settings_provider_win.h"
 
 #include <shellapi.h>
 
 #include "base/logging.h"
 #include "ui/views/widget/monitor_win.h"
@@ skipping 154 matching lines @@
     if (thickness != taskbars_[i].thickness) {
       taskbars_[i].thickness = thickness;
       thickness_changed = true;
     }
 
     // Check and notify the visibility change.
     DesktopBarVisibility visibility = GetDesktopBarVisibilityFromBounds(
         alignment, bounds);
     if (visibility != taskbars_[i].visibility) {
       taskbars_[i].visibility = visibility;
-      if (notify_observer && desktop_bar_observer()) {
-        desktop_bar_observer()->OnAutoHidingDesktopBarVisibilityChanged(
-            alignment, visibility);
+      if (notify_observer) {
+        FOR_EACH_OBSERVER(
+            DesktopBarObserver,
+            desktop_bar_observers(),
+            OnAutoHidingDesktopBarVisibilityChanged(alignment, visibility));
       }
     }
   }
 
   if (thickness_changed)
     OnAutoHidingDesktopBarChanged();
 
   return true;
 }
 
 // static
 DisplaySettingsProvider* DisplaySettingsProvider::Create() {
   return new DisplaySettingsProviderWin();
 }