Disable delegation to picker controller once it is deleted.

chrome/browser/ui/cocoa/web_intent_picker_cocoa.mm

 // 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.
 
 #include "chrome/browser/ui/cocoa/web_intent_picker_cocoa.h"
 
 #import <Cocoa/Cocoa.h>
 
 #include "base/bind.h"
 #include "base/message_loop.h"
@@ skipping 102 matching lines @@
 
 WebIntentPickerCocoa::~WebIntentPickerCocoa() {
   if (model_ != NULL)
     model_->set_observer(NULL);
 }
 
 void WebIntentPickerCocoa::OnSheetDidEnd(NSWindow* sheet) {
   [sheet orderOut:sheet_controller_];
   if (window_)
     window_->CloseConstrainedWindow();
-  delegate_->OnClosing();
+  if (delegate_)
+    delegate_->OnClosing();
 }
 
 void WebIntentPickerCocoa::Close() {
   DCHECK(sheet_controller_);
   [sheet_controller_ closeSheet];
 
   if (inline_disposition_tab_contents_.get())
     inline_disposition_tab_contents_->web_contents()->OnCloseStarted();
 }
 
@@ skipping 23 matching lines @@
 
 void WebIntentPickerCocoa::OnExtensionIconChanged(
     WebIntentPickerModel* model,
     const std::string& extension_id) {
   // We don't handle individual icon changes - just redo the whole model.
   PerformLayout();
 }
 
 void WebIntentPickerCocoa::OnInlineDisposition(const string16& title,
                                                const GURL& url) {
-
+  DCHECK(delegate_);
   content::WebContents* web_contents =
       delegate_->CreateWebContentsForInlineDisposition(
           tab_contents_->profile(), url);
   inline_disposition_tab_contents_.reset(
       TabContents::Factory::CreateTabContents(web_contents));
   Browser* browser = browser::FindBrowserWithWebContents(
       tab_contents_->web_contents());
   inline_disposition_delegate_.reset(
       new WebIntentInlineDispositionDelegate(this, web_contents, browser));
 
@@ skipping 22 matching lines @@
   const WebIntentPickerModel::InstalledService& installed_service =
       model_->GetInstalledServiceAt(index);
   service_invoked = true;
   delegate_->OnServiceChosen(installed_service.url,
                              installed_service.disposition,
                              WebIntentPickerDelegate::kEnableDefaults);
 }
 
 void WebIntentPickerCocoa::OnExtensionInstallRequested(
     const std::string& extension_id) {
+  DCHECK(delegate_);
   delegate_->OnExtensionInstallRequested(extension_id);
 }
 
 void WebIntentPickerCocoa::OnExtensionInstallSuccess(const std::string& id) {
   DCHECK(sheet_controller_);
   [sheet_controller_ stopThrobber];
 }
 
 void WebIntentPickerCocoa::OnExtensionInstallFailure(const std::string& id) {
   // TODO(groby): What to do on failure? (See also binji for views/gtk)
   DCHECK(sheet_controller_);
   [sheet_controller_ stopThrobber];
 }
 
 void WebIntentPickerCocoa::OnInlineDispositionAutoResize(
     const gfx::Size& size) {
   DCHECK(sheet_controller_);
   NSSize inline_content_size = NSMakeSize(size.width(), size.height());
   [sheet_controller_ setInlineDispositionFrameSize:inline_content_size];
 }
 
 void WebIntentPickerCocoa::OnPendingAsyncCompleted() {
 }
 
+void WebIntentPickerCocoa::InvalidateDelegate() {
+  delegate_ = NULL;
+}
+
 void WebIntentPickerCocoa::OnExtensionLinkClicked(
     const std::string& id,
     WindowOpenDisposition disposition) {
   DCHECK(delegate_);
   delegate_->OnExtensionLinkClicked(id, disposition);
 }
 
 void WebIntentPickerCocoa::OnSuggestionsLinkClicked(
     WindowOpenDisposition disposition) {
   DCHECK(delegate_);
   delegate_->OnSuggestionsLinkClicked(disposition);
 }
 
 void WebIntentPickerCocoa::OnChooseAnotherService() {
   DCHECK(delegate_);
   delegate_->OnChooseAnotherService();
   inline_disposition_tab_contents_.reset();
   inline_disposition_delegate_.reset();
   [sheet_controller_ setInlineDispositionTabContents:NULL];
   PerformLayout();
 }