Removes unnecessary function in WmWindow

ash/wm/aura/wm_window_aura.cc

Index: ash/wm/aura/wm_window_aura.cc
diff --git a/ash/wm/aura/wm_window_aura.cc b/ash/wm/aura/wm_window_aura.cc
index 2a09ff622254e87dc08547ecd4e15e23d966b1a9..6d4fd902a86fabf4499c46d1942d4a15c5672740 100644
--- a/ash/wm/aura/wm_window_aura.cc
+++ b/ash/wm/aura/wm_window_aura.cc
@@ -357,10 +357,6 @@ gfx::Rect WmWindowAura::GetRestoreBoundsInScreen() const {
   return *window_->GetProperty(aura::client::kRestoreBoundsKey);
 }
 
-void WmWindowAura::OnWMEvent(const wm::WMEvent* event) {
-  ash::wm::GetWindowState(window_)->OnWMEvent(event);
-}
-
 bool WmWindowAura::Contains(const WmWindow* other) const {
   return other
              ? window_->Contains(