cros: Update rotation lock UI

ash/system/tray/tray_image_item.h

Index: ash/system/tray/tray_image_item.h
diff --git a/ash/system/tray/tray_image_item.h b/ash/system/tray/tray_image_item.h
index 64fdb96c7084a1e8b14bfd8b651e1a61232ac65c..ff4402f5e128f765d4723e5fc2448af5e332fc14 100644
--- a/ash/system/tray/tray_image_item.h
+++ b/ash/system/tray/tray_image_item.h
@@ -41,10 +41,10 @@ class ASH_EXPORT TrayImageItem : public SystemTrayItem {
   // Sets the color of the icon to |color|.
   void SetIconColor(SkColor color);
 
- private:
-  // Sets the current icon on |tray_view_|'s ImageView.
-  void UpdateImageOnImageView();
+  // Sets showing |icon| on |tray_view_|'s ImageView.
+  void SetImageIcon(const gfx::VectorIcon& icon);
 
+ private:
   // The icon and its current color.
   const gfx::VectorIcon& icon_;
   SkColor icon_color_;