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

ui/views/widget/widget.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_WIDGET_WIDGET_H_
 #define UI_VIEWS_WIDGET_WIDGET_H_
 
 #include <set>
 #include <stack>
 #include <vector>
@@ skipping 775 matching lines @@
   // Creates the RootView to be used within this Widget. Subclasses may override
   // to create custom RootViews that do specialized event processing.
   // TODO(beng): Investigate whether or not this is needed.
   virtual internal::RootView* CreateRootView();
 
   // Provided to allow the NativeWidget implementations to destroy the RootView
   // _before_ the focus manager/tooltip manager.
   // TODO(beng): remove once we fold those objects onto this one.
   void DestroyRootView();
 
+  // Notification that the drag performed by RunShellDrag() has completed.
+  // Default implementation does nothing.
+  virtual void OnDragComplete();

[sky, 2014/07/11 17:45:34]

You should move the code in MenuController::StartDrag so that state is set
correctly if a drag is initiated outside of the menu code. I believe this means
adding a method like OnDragWillStart() here having MenuHost override and forward
to MenuController. MenuController's OnDragWillStart would set drag_in_progress_.
A similar flow should happen at the end of the drag to either reset capture or
close menus.

[Devlin, 2014/07/11 18:43:51]

Done (though not much of the code in StartDrag() is relevant, since the drag is
initiated and handled through the other View).

[sky, 2014/07/11 19:15:20]

I wanted to make sure the state (which you're right, is only one boolean) is set
consistently for both cases. That's why moving to the method that is always
invoked is ideal.

[Devlin, 2014/07/11 20:28:15]

Yep, makes a lot of sense. :)  Just wanted to make sure that the only state that
applied was the bool, and that I wasn't missing something.

+
  private:
   friend class ComboboxTest;
   friend class TextfieldTest;
 
   // Sets the value of |disable_inactive_rendering_|. If the value changes,
   // both the NonClientView and WidgetDelegate are notified.
   void SetInactiveRenderingDisabled(bool value);
 
   // Persists the window's restored position and "show" state using the
   // window delegate.
@@ skipping 122 matching lines @@
   bool movement_disabled_;
 
   ScopedObserver<ui::NativeTheme, ui::NativeThemeObserver> observer_manager_;
 
   DISALLOW_COPY_AND_ASSIGN(Widget);
 };
 
 }  // namespace views
 
 #endif  // UI_VIEWS_WIDGET_WIDGET_H_