Save display preference when all display configuration changes has been completed.

chrome/browser/chromeos/display/display_preferences.cc

 // 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.
 
 #include "chrome/browser/chromeos/display/display_preferences.h"
 
 #include "ash/display/display_controller.h"
 #include "ash/display/display_manager.h"
 #include "ash/shell.h"
 #include "base/prefs/pref_registry_simple.h"
@@ skipping 162 matching lines @@
   ash::DisplayController* display_controller = GetDisplayController();
   ash::DisplayLayout display_layout =
       display_controller->GetCurrentDisplayLayout();
   ash::DisplayIdPair pair = display_controller->GetCurrentDisplayIdPair();
 
   StoreDisplayLayoutPref(pair.first, pair.second, display_layout);
 }
 
 
 void StorePrimaryDisplayIDPref(int64 display_id) {
-  if (!IsValidUser())
+  if (!IsValidUser() || gfx::Screen::GetNativeScreen()->GetNumDisplays() < 2)
     return;
 
   PrefService* local_state = g_browser_process->local_state();
   if (GetDisplayManager()->IsInternalDisplayId(display_id))
     local_state->ClearPref(prefs::kPrimaryDisplayID);
   else
     local_state->SetInt64(prefs::kPrimaryDisplayID, display_id);
 }
 
 }  // namespace
@@ skipping 10 matching lines @@
 
   // Primary output name.
   registry->RegisterInt64Pref(prefs::kPrimaryDisplayID,
                               gfx::Display::kInvalidDisplayID);
 
   // Display overscan preference.
   registry->RegisterDictionaryPref(prefs::kDisplayOverscans);
 }
 
 void StoreDisplayPrefs() {
-  StorePrimaryDisplayIDPref(ash::Shell::GetScreen()->GetPrimaryDisplay().id());
-  StoreCurrentDisplayLayoutPrefs();
+  if (!IsValidUser())
+    return;
+  if (gfx::Screen::GetNativeScreen()->GetNumDisplays() == 2) {
+    StorePrimaryDisplayIDPref(
+        ash::Shell::GetScreen()->GetPrimaryDisplay().id());
+    StoreCurrentDisplayLayoutPrefs();
+  }
 }
 
 void SetAndStoreDisplayLayoutPref(int layout, int offset) {
   ash::DisplayLayout display_layout(
       static_cast<ash::DisplayLayout::Position>(layout), offset);
   ash::Shell::GetInstance()->display_controller()->
       SetLayoutForCurrentDisplays(display_layout);
   StoreCurrentDisplayLayoutPrefs();
 }
 
@@ skipping 29 matching lines @@
 
 void NotifyDisplayLocalStatePrefChanged() {
   PrefService* local_state = g_browser_process->local_state();
   ash::Shell::GetInstance()->display_controller()->SetPrimaryDisplayId(
       local_state->GetInt64(prefs::kPrimaryDisplayID));
   NotifyDisplayLayoutChanged();
   NotifyDisplayOverscans();
 }
 
 }  // namespace chromeos