Disable delegation to picker controller once it is deleted.

chrome/browser/ui/intents/web_intent_picker.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 CHROME_BROWSER_UI_INTENTS_WEB_INTENT_PICKER_H_
 #define CHROME_BROWSER_UI_INTENTS_WEB_INTENT_PICKER_H_
 
 #include <stddef.h>
 #include <string>
 #include <vector>
@@ skipping 85 matching lines @@
   // Called when the inline disposition experiences an auto-resize.
   virtual void OnInlineDispositionAutoResize(const gfx::Size& size) = 0;
 
   virtual void OnInlineDispositionHandleKeyboardEvent(
       const content::NativeWebKeyboardEvent& event) {}
 
   // Called when the controller has finished all pending asynchronous
   // activities.
   virtual void OnPendingAsyncCompleted() = 0;
 
+  // Called once the delegate gets destroyed/invalid. This should only be
+  // called during a shut down sequence that will tear down the picker, too.
+  virtual void InvalidateDelegate() = 0;
+
   // Called when the inline disposition's web contents have been loaded.
   virtual void OnInlineDispositionWebContentsLoaded(
       content::WebContents* web_contents) {}
 
   // Get the minimum size of the inline disposition content container.
   virtual gfx::Size GetMinInlineDispositionSize();
 
   // Get the maximum size of the inline disposition content container.
   virtual gfx::Size GetMaxInlineDispositionSize();
 
   // Get the star image IDs to use for the nth star (out of 5), given a
   // |rating| in the range [0, 5].
   static int GetNthStarImageIdFromCWSRating(double rating, int index);
 
   // Returns the action-specific string to display for |action|.
   static string16 GetDisplayStringForIntentAction(const string16& action16);
 
  protected:
   virtual ~WebIntentPicker() {}
 };
 
 #endif  // CHROME_BROWSER_UI_INTENTS_WEB_INTENT_PICKER_H_