Fix even more crashes. To help identify remaining crashes now and in the future, I have made the ...

views/widget/widget_delegate.h

 // Copyright (c) 2011 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 VIEWS_WIDGET_WIDGET_DELEGATE_H_
 #define VIEWS_WIDGET_WIDGET_DELEGATE_H_
 #pragma once
 
 #include <string>
 
@@ skipping 117 matching lines @@
   virtual void DeleteDelegate() {}
 
   // Called when the window's activation state changes.
   virtual void OnWindowActivationChanged(bool active) {}
 
   // Called when the user begins/ends to change the bounds of the window.
   virtual void OnWindowBeginUserBoundsChange() {}
   virtual void OnWindowEndUserBoundsChange() {}
 
   // Returns the Widget associated with this delegate.
-  virtual Widget* GetWidget();
-  virtual const Widget* GetWidget() const;
+  virtual Widget* GetWidget() = 0;
+  virtual const Widget* GetWidget() const = 0;
 
   // Returns the View that is contained within this Widget.
   virtual View* GetContentsView();
 
   // Called by the Widget to create the Client View used to host the contents
   // of the widget.
   virtual ClientView* CreateClientView(Widget* widget);
 
   // Called by the Widget to create the NonClient Frame View for this widget.
   // Return NULL to use the default one.
@@ skipping 28 matching lines @@
   virtual const Widget* GetWidget() const OVERRIDE;
 
  private:
   DISALLOW_COPY_AND_ASSIGN(WidgetDelegateView);
 };
 
 }  // namespace views
 
 #endif  // VIEWS_WIDGET_WIDGET_DELEGATE_H_