chromeos: changes how DisplayManagerObservers are notified

services/ui/ws/user_display_manager.h

 // 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.
 
 #ifndef SERVICES_UI_WS_USER_DISPLAY_MANAGER_H_
 #define SERVICES_UI_WS_USER_DISPLAY_MANAGER_H_
 
 #include <vector>
 
 #include "base/macros.h"
@@ skipping 11 matching lines @@
 
 class UserDisplayManagerDelegate;
 
 // Provides per user display state.
 class UserDisplayManager : public mojom::DisplayManager {
  public:
   UserDisplayManager(UserDisplayManagerDelegate* delegate,
                      const UserId& user_id);
   ~UserDisplayManager() override;
 
+  void DisableAutomaticNotification();
+
+  // Unconditionally calls OnDisplayChanged() on observers.
+  void CallOnDisplaysChanged();
+
   // Called when the frame decorations for this user change.
   void OnFrameDecorationValuesChanged();
 
   void AddDisplayManagerBinding(
       mojo::InterfaceRequest<mojom::DisplayManager> request);
 
   // Called when something about the display (e.g. pixel-ratio, size) changes.
   void OnDisplayUpdated(const display::Display& display);
 
   // Called when the display with |display_id| was removed.
@@ skipping 29 matching lines @@
 
   // Set to true the first time at least one Display has valid frame values.
   bool got_valid_frame_decorations_;
 
   mojo::BindingSet<mojom::DisplayManager> display_manager_bindings_;
 
   // WARNING: only use these once |got_valid_frame_decorations_| is true.
   mojo::InterfacePtrSet<mojom::DisplayManagerObserver>
       display_manager_observers_;
 
+  // If true DisplayManagerObservers are notified any time there is a display
+  // change. If false, observers are only notified when CallOnDisplaysChanged()
+  // is explicitly called. This value is true in automatic display creation and
+  // false when in manual mode.
+  bool notify_automatically_ = true;
+
   DISALLOW_COPY_AND_ASSIGN(UserDisplayManager);
 };
 
 }  // namespace ws
 }  // namespace ui
 
 #endif  // SERVICES_UI_WS_USER_DISPLAY_MANAGER_H_