ash: Remove unnecessary WmShelf::SchedulePaint() method

ash/shelf/shelf.cc

Index: ash/shelf/shelf.cc
diff --git a/ash/shelf/shelf.cc b/ash/shelf/shelf.cc
index 1b4e2c879a5cef5de5a94ef51c92fd834ddd3c63..071a57bc6e393b9d563cddceb65a8c7e20da00ed 100644
--- a/ash/shelf/shelf.cc
+++ b/ash/shelf/shelf.cc
@@ -148,10 +148,6 @@ bool Shelf::IsVisible() const {
   return shelf_view_->visible();
 }
 
-void Shelf::SchedulePaint() {
-  shelf_view_->SchedulePaintForAllButtons();
-}
-
 AppListButton* Shelf::GetAppListButton() const {
   return shelf_view_->GetAppListButton();
 }