Allow menus to stay open during a child view's drag and drop

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 fdcb32af915e97a73fead05becf0ac0c83dece35..54c810962983a79cce587de2f7f1c3948af0ab00 100644
--- a/ui/views/widget/widget.cc
+++ b/ui/views/widget/widget.cc
@@ -787,6 +787,7 @@ void Widget::RunShellDrag(View* view,
                           int operation,
                           ui::DragDropTypes::DragEventSource source) {
   dragged_view_ = view;
+  OnDragWillStart();
   native_widget_->RunShellDrag(view, data, location, operation, source);
   // If the view is removed during the drag operation, dragged_view_ is set to
   // NULL.
@@ -794,6 +795,7 @@ void Widget::RunShellDrag(View* view,
     dragged_view_ = NULL;
     view->OnDragDone();
   }
+  OnDragComplete(view);
 }
 
 void Widget::SchedulePaintInRect(const gfx::Rect& rect) {
@@ -1395,6 +1397,12 @@ void Widget::DestroyRootView() {
   input_method_.reset();
 }
 
+void Widget::OnDragWillStart() {
+}
+
+void Widget::OnDragComplete(View* view) {
+}
+
 ////////////////////////////////////////////////////////////////////////////////
 // Widget, private: