app_list: Fix shadow bleeds over launcher button and steals mouse events

ui/views/widget/widget.cc

Index: ui/views/widget/widget.cc
diff --git a/ui/views/widget/widget.cc b/ui/views/widget/widget.cc
index 62a395c305a6026dbf0ac4c336a892fc3aed9b73..6f9938ba6c522d7caf55fe72067c8a453d167dad 100644
--- a/ui/views/widget/widget.cc
+++ b/ui/views/widget/widget.cc
@@ -1130,6 +1130,15 @@ InputMethod* Widget::GetInputMethodDirect() {
   return input_method_.get();
 }
 
+bool Widget::HasHitTestMask() const {
+  return widget_delegate_->HasHitTestMask();
+}
+
+void Widget::GetHitTestMask(gfx::Path* mask) const {
+  DCHECK(mask);
+  widget_delegate_->GetHitTestMask(mask);
+}
+
 Widget* Widget::AsWidget() {
   return this;
 }