ash: Remove broken display notification suppression when settings is open

ash/system/chromeos/screen_layout_observer.h

 // 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.
 
 #ifndef ASH_SYSTEM_CHROMEOS_SCREEN_LAYOUT_OBSERVER_H_
 #define ASH_SYSTEM_CHROMEOS_SCREEN_LAYOUT_OBSERVER_H_
 
 #include <stdint.h>
 
 #include <map>
@@ skipping 11 matching lines @@
 // ScreenLayoutObserver is responsible to send notification to users when screen
 // resolution changes or screen rotation changes.
 class ASH_EXPORT ScreenLayoutObserver : public WmDisplayObserver {
  public:
   ScreenLayoutObserver();
   ~ScreenLayoutObserver() override;
 
   // Overridden from WmDisplayObserver:
   void OnDisplayConfigurationChanged() override;
 
+  // Allow tests to suppress showing notifications.

[oshima, 2016/10/11 20:50:34]

nit: update the comment. (or clarify as it sounds confusing)
it's probably better to say the default is true (allowed) but false in unit
tests.

[James Cook, 2016/10/11 20:58:17]

Done.

+  void set_show_notifications_for_testing(bool show) {
+    show_notifications_for_testing = show;
+  }
+
  private:
   friend class ScreenLayoutObserverTest;
 
   using DisplayInfoMap = std::map<int64_t, display::ManagedDisplayInfo>;
 
   static const char kNotificationId[];
 
   // Scans the current display info and updates |display_info_|. Sets the
   // previous data to |old_info| if it's not NULL.
   void UpdateDisplayInfo(DisplayInfoMap* old_info);
 
   // Compares the current display settings with |old_info| and determine what
   // message should be shown for notification. Returns true if there's a
   // meaningful change. Note that it's possible to return true and set
   // |message_out| to empty, which means the notification should be removed. It
   // also sets |additional_message_out| which appears in the notification with
   // the |message_out|.
   bool GetDisplayMessageForNotification(const DisplayInfoMap& old_info,
                                         base::string16* message_out,
                                         base::string16* additional_message_out);
 
   // Creates or updates the display notification.
   void CreateOrUpdateNotification(const base::string16& message,
                                   const base::string16& additional_message);
 
   DisplayInfoMap display_info_;
 
+  bool show_notifications_for_testing = true;
+
   DISALLOW_COPY_AND_ASSIGN(ScreenLayoutObserver);
 };
 
 }  // namespace ash
 
 #endif  // ASH_SYSTEM_CHROMEOS_SCREEN_LAYOUT_OBSERVER_H_