Revert of Save and restore unified mode

ash/display/display_manager.cc

Index: ash/display/display_manager.cc
diff --git a/ash/display/display_manager.cc b/ash/display/display_manager.cc
index 24e2bc18f47ac89fc7f6a44a55383aef78ef391d..92c0f59f5966f78a81f058e788c52ed392615ba0 100644
--- a/ash/display/display_manager.cc
+++ b/ash/display/display_manager.cc
@@ -140,6 +140,9 @@
   if (base::SysInfo::IsRunningOnChromeOS())
     DisplayInfo::SetUse125DSFForUIScaling(true);
 
+  if (switches::UnifiedDesktopEnabled())
+    default_multi_display_mode_ = UNIFIED;
+
   change_display_upon_host_resize_ = !base::SysInfo::IsRunningOnChromeOS();
 #endif
   gfx::Screen::SetScreenInstance(gfx::SCREEN_TYPE_ALTERNATE, screen_.get());
@@ -638,8 +641,6 @@
   if (gfx::Display::HasInternalDisplay() && !internal_display_connected &&
       display_info_.find(gfx::Display::InternalDisplayId()) ==
           display_info_.end()) {
-    // Create a dummy internal display if the chrome restarted
-    // in docked mode.
     DisplayInfo internal_display_info(
         gfx::Display::InternalDisplayId(),
         l10n_util::GetStringUTF8(IDS_ASH_INTERNAL_DISPLAY_NAME),
@@ -647,25 +648,6 @@
     internal_display_info.SetBounds(gfx::Rect(0, 0, 800, 600));
     display_info_[gfx::Display::InternalDisplayId()] = internal_display_info;
   }
-
-#if defined(OS_CHROMEOS)
-  if (new_display_info_list.size() > 1) {
-    std::sort(new_display_info_list.begin(), new_display_info_list.end(),
-              DisplayInfoSortFunctor());
-    DisplayIdPair pair = std::make_pair(new_display_info_list[0].id(),
-                                        new_display_info_list[1].id());
-    DisplayLayout layout = layout_store_->GetRegisteredDisplayLayout(pair);
-    default_multi_display_mode_ =
-        (layout.default_unified && switches::UnifiedDesktopEnabled())
-            ? UNIFIED
-            : EXTENDED;
-    // Mirror mode is set by DisplayConfigurator on the device.
-    // Emulate it when running on linux desktop.
-    if (!base::SysInfo::IsRunningOnChromeOS() && layout.mirrored)
-      SetMultiDisplayMode(MIRRORING);
-  }
-#endif
-
   UpdateDisplays(new_display_info_list);
 }