Allow idle/suspend with 3+ monitors attached

ui/display/chromeos/update_display_configuration_task.cc

 // Copyright 2014 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 "ui/display/chromeos/update_display_configuration_task.h"
 
 #include "ui/display/chromeos/configure_displays_task.h"
 #include "ui/display/chromeos/display_layout_manager.h"
 #include "ui/display/chromeos/display_util.h"
 #include "ui/display/types/display_snapshot.h"
@@ skipping 186 matching lines @@
   if (num_displays == 2 || num_on_displays == 2) {
     // Try to use the saved configuration; otherwise, default to extended.
     DisplayConfigurator::StateController* state_controller =
         layout_manager_->GetStateController();
 
     if (!state_controller)
       return MULTIPLE_DISPLAY_STATE_DUAL_EXTENDED;
     return state_controller->GetStateForDisplayIds(cached_displays_);
   }
 
-  if (num_on_displays >= 3) {
+  if (num_displays >= 3) {
     // 3+ displays are always extended
     return MULTIPLE_DISPLAY_STATE_MULTI_EXTENDED;
   }
 
   return MULTIPLE_DISPLAY_STATE_INVALID;
 }
 
 }  // namespace ui