Make shelf item can be dragged when context menu is opened.

ash/shelf/shelf_view.cc

Index: ash/shelf/shelf_view.cc
diff --git a/ash/shelf/shelf_view.cc b/ash/shelf/shelf_view.cc
index acbef66d2ed93e81dc6576c84ddf59074dbc642c..91e9294d6df228c6ebd43be798153b024e1750c3 100644
--- a/ash/shelf/shelf_view.cc
+++ b/ash/shelf/shelf_view.cc
@@ -654,6 +654,8 @@ bool ShelfView::ShouldEventActivateButton(View* view, const ui::Event& event) {
 void ShelfView::PointerPressedOnButton(views::View* view,
                                        Pointer pointer,
                                        const ui::LocatedEvent& event) {
+  if (IsShowingMenu())
+    launcher_menu_runner_->Cancel();
   if (drag_view_)
     return;
 
@@ -1683,7 +1685,7 @@ void ShelfView::ShowContextMenuForView(views::View* source,
   last_pressed_index_ = -1;
 
   const ShelfItem* item = ShelfItemForView(source);
-  if (!item) {
+  if (!item || item->type == TYPE_APP_LIST) {
     ShellPort::Get()->ShowContextMenu(context_menu_point, source_type);
     return;
   }
@@ -1714,6 +1716,11 @@ void ShelfView::ShowMenu(std::unique_ptr<ui::MenuModel> menu_model,
   if (context_menu)
     run_types |=
         views::MenuRunner::CONTEXT_MENU | views::MenuRunner::FIXED_ANCHOR;
+
+  // Shelf items can only be dragged if the shelf is not in auto-hide.
+  if (shelf()->auto_hide_behavior() == SHELF_AUTO_HIDE_BEHAVIOR_NEVER)
+    run_types |= views::MenuRunner::SEND_GESTURE_EVENTS_TO_OWNER;
+
   launcher_menu_runner_.reset(
       new views::MenuRunner(menu_model_adapter_->CreateMenu(), run_types));
 
@@ -1766,10 +1773,6 @@ void ShelfView::ShowMenu(std::unique_ptr<ui::MenuModel> menu_model,
 void ShelfView::OnMenuClosed(views::InkDrop* ink_drop) {
   context_menu_id_ = ShelfID();
 
-  // Hide the hide overflow bubble after showing a context menu for its items.
-  if (owner_overflow_bubble_)
-    owner_overflow_bubble_->Hide();
-
   closing_event_time_ = launcher_menu_runner_->closing_event_time();
 
   if (ink_drop)