Store rotation/ui scale to local state.

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 de75d8346353ad23a6e1ebd1ccab139fc3d81b3d..685c9bb87e4975e0b73c62648202ebbc20c8e48d 100644
--- a/ash/display/display_manager.cc
+++ b/ash/display/display_manager.cc
@@ -338,6 +338,17 @@ void DisplayManager::OnNativeDisplaysChanged(
 }
 
 void DisplayManager::UpdateDisplays() {
+#if defined(OS_CHROMEOS)
+  if (displays_.size() > 0 && base::chromeos::IsRunningOnChromeOS()) {
+    const DisplayLayout& layout = Shell::GetInstance()->
+        display_controller()->GetCurrentDisplayLayout();
+    if (layout.mirrored) {
+      Shell::GetInstance()->output_configurator()->
+          SetDisplayMode(chromeos::STATE_DUAL_MIRROR);
+    }
+    return;
+  }
+#endif
   DisplayInfoList display_info_list;
   for (DisplayList::const_iterator iter = displays_.begin();
        iter != displays_.end(); ++iter) {