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

ui/views/controls/menu/menu_controller.h

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef UI_VIEWS_CONTROLS_MENU_MENU_CONTROLLER_H_
 #define UI_VIEWS_CONTROLS_MENU_MENU_CONTROLLER_H_
 
 #include <stddef.h>
 
 #include <list>
@@ skipping 112 matching lines @@
 
   // Returns the current exit type. This returns a value other than EXIT_NONE if
   // the menu is being canceled.
   ExitType exit_type() const { return exit_type_; }
 
   // Returns the time from the event which closed the menu - or 0.
   base::TimeTicks closing_event_time() const { return closing_event_time_; }
 
   void set_is_combobox(bool is_combobox) { is_combobox_ = is_combobox; }
 
+  void set_cancel_active_touches(bool cancel_active_touches) {
+    cancel_active_touches_ = cancel_active_touches;
+  }
   // Various events, forwarded from the submenu.
   //
   // NOTE: the coordinates of the events are in that of the
   // MenuScrollViewContainer.
   bool OnMousePressed(SubmenuView* source, const ui::MouseEvent& event);
   bool OnMouseDragged(SubmenuView* source, const ui::MouseEvent& event);
   void OnMouseReleased(SubmenuView* source, const ui::MouseEvent& event);
   void OnMouseMoved(SubmenuView* source, const ui::MouseEvent& event);
   void OnMouseEntered(SubmenuView* source, const ui::MouseEvent& event);
   bool OnMouseWheel(SubmenuView* source, const ui::MouseWheelEvent& event);
@@ skipping 517 matching lines @@
   base::TimeTicks menu_start_time_;
 
   // If a mouse press triggered this menu, this will have its location (in
   // screen coordinates). Otherwise this will be (0, 0).
   gfx::Point menu_start_mouse_press_loc_;
 
   // Controls behavior differences between a combobox and other types of menu
   // (like a context menu).
   bool is_combobox_;
 
+  // In order to make item can be dragged after context menu is opened. Cannot
+  // cancel existing touch events.
+  bool cancel_active_touches_ = true;
+
   // Set to true if the menu item was selected by touch.
   bool item_selected_by_touch_;
 
   // During mouse event handling, this is the RootView to forward mouse events
   // to. We need this, because if we forward one event to it (e.g., mouse
   // pressed), subsequent events (like dragging) should also go to it, even if
   // the mouse is no longer over the view.
   MenuHostRootView* current_mouse_event_target_;
 
   // A mask of the EventFlags for the mouse buttons currently pressed.
   int current_mouse_pressed_state_;
 
 #if defined(USE_AURA)
   std::unique_ptr<MenuPreTargetHandler> menu_pre_target_handler_;
 #endif
 
   DISALLOW_COPY_AND_ASSIGN(MenuController);
 };
 
 }  // namespace views
 
 #endif  // UI_VIEWS_CONTROLS_MENU_MENU_CONTROLLER_H_