Store rotation/ui scale to local state.

ash/display/display_controller.h

Index: ash/display/display_controller.h
diff --git a/ash/display/display_controller.h b/ash/display/display_controller.h
index 3927dc2c92b4ec4b8d5da9423eea6b0f2677868b..65260c4fc58e42830959d302ac033b2f1cb4dfcb 100644
--- a/ash/display/display_controller.h
+++ b/ash/display/display_controller.h
@@ -46,10 +46,10 @@ struct ASH_EXPORT DisplayLayout {
   };
   // Factory method to create DisplayLayout from int values.
   // Used for persistence and webui.
-  static DisplayLayout FromInts(int position, int offsets);
+  static DisplayLayout FromInts(int position, int offsets, bool mirror);
 
   DisplayLayout();
-  DisplayLayout(Position position, int offset);
+  DisplayLayout(Position position, int offset, bool mirrored);
 
   // Returns an inverted display layout.
   DisplayLayout Invert() const WARN_UNUSED_RESULT;
@@ -69,6 +69,8 @@ struct ASH_EXPORT DisplayLayout {
   // based on the top/left edge of the primary display.
   int offset;
 
+  bool mirrored;
+
   // Returns string representation of the layout for debugging/testing.
   std::string ToString() const;
 };