Refactor and push window properties up to class properties.

ui/aura/window_port_local.cc

Index: ui/aura/window_port_local.cc
diff --git a/ui/aura/window_port_local.cc b/ui/aura/window_port_local.cc
index 9037c2602116afcb72a7d62db2d00c3a1ba311d7..746f5e48bb2cd34945df4e888833d88d976d2ee8 100644
--- a/ui/aura/window_port_local.cc
+++ b/ui/aura/window_port_local.cc
@@ -79,13 +79,13 @@ void WindowPortLocal::OnVisibilityChanged(bool visible) {}
 void WindowPortLocal::OnDidChangeBounds(const gfx::Rect& old_bounds,
                                         const gfx::Rect& new_bounds) {}
 
-std::unique_ptr<WindowPortPropertyData> WindowPortLocal::OnWillChangeProperty(
+std::unique_ptr<ui::PropertyData> WindowPortLocal::OnWillChangeProperty(
     const void* key) {
   return nullptr;
 }
 
 void WindowPortLocal::OnPropertyChanged(
     const void* key,
-    std::unique_ptr<WindowPortPropertyData> data) {}
+    std::unique_ptr<ui::PropertyData> data) {}
 
 }  // namespace aura