Temporary fix to return only the active displays.

ash/display/display_manager.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_DISPLAY_DISPLAY_MANAGER_H_
 #define ASH_DISPLAY_DISPLAY_MANAGER_H_
 
 #include <stddef.h>
 #include <stdint.h>
 
@@ skipping 219 matching lines @@
   // Returns the display at |index|. The display at 0 is
   // no longer considered "primary".
   const display::Display& GetDisplayAt(size_t index) const;
 
   const display::Display& GetPrimaryDisplayCandidate() const;
 
   // Returns the logical number of displays. This returns 1
   // when displays are mirrored.
   size_t GetNumDisplays() const;
 
+  // Returns only the currently active displays. This list does not include the
+  // displays that will be removed if |UpdateDisplaysWith| is currently
+  // executing.
+  // See https://crbug.com/632755
+  const display::DisplayList& active_only_display_list() const {
+    return is_updating_display_list_ ? active_only_display_list_
+                                     : active_display_list();
+  }
+
   const display::DisplayList& active_display_list() const {
     return active_display_list_;
   }
 
   // Returns true if the display specified by |display_id| is currently
   // connected and active. (mirroring display isn't active, for example).
   bool IsActiveDisplayId(int64_t display_id) const;
 
   // Returns the number of connected displays. This returns 2
   // when displays are mirrored.
@@ skipping 155 matching lines @@
   Delegate* delegate_;  // not owned.
 
   std::unique_ptr<ScreenAsh> screen_;
 
   std::unique_ptr<DisplayLayoutStore> layout_store_;
 
   int64_t first_display_id_;
 
   // List of current active displays.
   display::DisplayList active_display_list_;
+  // This list does not include the displays that will be removed if
+  // |UpdateDisplaysWith| is under execution.
+  // See https://crbug.com/632755
+  display::DisplayList active_only_display_list_;
+
+  // True if active_display_list is being modified and has displays that are not
+  // presently active.
+  // See https://crbug.com/632755
+  bool is_updating_display_list_;

[oshima, 2016/08/17 01:21:08]

nit:  = false;

 
   int num_connected_displays_;
 
   bool force_bounds_changed_;
 
   // The mapping from the display ID to its internal data.
   std::map<int64_t, DisplayInfo> display_info_;
 
   // Selected display modes for displays. Key is the displays' ID.
   std::map<int64_t, scoped_refptr<DisplayMode>> display_modes_;
@@ skipping 20 matching lines @@
   bool unified_desktop_enabled_;
 
   base::WeakPtrFactory<DisplayManager> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(DisplayManager);
 };
 
 }  // namespace ash
 
 #endif  // ASH_DISPLAY_DISPLAY_MANAGER_H_