chromeos: Move files in //ash/common to //ash, part 1

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>
-
-#include "ash/ash_export.h"
-#include "ash/common/wm_display_observer.h"
-#include "base/macros.h"
-#include "base/strings/string16.h"
-#include "ui/display/manager/managed_display_info.h"
-
-namespace ash {
-
-// 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;
-
-  // Notifications are shown in production and are not shown in unit tests.
-  // Allow individual unit tests to show notifications.
-  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* out_message,
-                                        base::string16* out_additional_message);
-
-  // Creates or updates the display notification.
-  void CreateOrUpdateNotification(const base::string16& message,
-                                  const base::string16& additional_message);
-
-  // Returns the notification message that should be shown when mirror display
-  // mode is exited.
-  bool GetExitMirrorModeMessage(base::string16* out_message,
-                                base::string16* out_additional_message);
-
-  DisplayInfoMap display_info_;
-
-  enum class DisplayMode {
-    SINGLE,
-    EXTENDED_2,       // 2 displays in extended mode.
-    EXTENDED_3_PLUS,  // 3+ displays in extended mode.
-    MIRRORING,
-    UNIFIED,
-    DOCKED
-  };
-
-  DisplayMode old_display_mode_ = DisplayMode::SINGLE;
-  DisplayMode current_display_mode_ = DisplayMode::SINGLE;
-
-  bool show_notifications_for_testing = true;
-
-  DISALLOW_COPY_AND_ASSIGN(ScreenLayoutObserver);
-};
-
-}  // namespace ash
-
-#endif  // ASH_SYSTEM_CHROMEOS_SCREEN_LAYOUT_OBSERVER_H_