Avert crash in ExtensionInstalledBubbleView::GetWindowTitle triggered

chrome/browser/ui/views/extensions/extension_installed_bubble_view.cc

 // Copyright 2013 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 <algorithm>
 #include <string>
 
 #include "base/macros.h"
 #include "base/memory/ptr_util.h"
 #include "base/metrics/user_metrics_action.h"
@@ skipping 152 matching lines @@
         BrowserView::GetBrowserViewForBrowser(browser());
     browser_view->GetLocationBarView()->SetPreviewEnabledPageAction(
         extensions::ExtensionActionManager::Get(browser()->profile())
             ->GetPageAction(*controller_->extension()),
         false);  // preview_enabled
   }
   controller_ = nullptr;
   GetWidget()->Close();
 }
 
 base::string16 ExtensionInstalledBubbleView::GetWindowTitle() const {

[Devlin, 2016/09/20 20:15:43]

Is there any way we could detect the view is closed, and if so, would this be
better handled higher up the chain (e.g. DialogDelegateView, View, etc)?  This
seems like something that could happen to any view rather than just this one.

+  // This may be called by screen readers after the window is closed.
+  // See crbug.com/648280
+  if (!controller_)
+    return base::string16();
+
   // Add the heading (for all options).
   base::string16 extension_name =
       base::UTF8ToUTF16(controller_->extension()->name());
   base::i18n::AdjustStringForLocaleDirection(&extension_name);
   return l10n_util::GetStringFUTF16(IDS_EXTENSION_INSTALLED_HEADING,
                                     extension_name);
 }
 
 gfx::ImageSkia ExtensionInstalledBubbleView::GetWindowIcon() {
   const SkBitmap& bitmap = controller_->icon();
@@ skipping 169 matching lines @@
             ->browser_actions();
     return !container->animating();
   }
   return true;
 }
 
 // Implemented here to create the platform specific instance of the BubbleUi.
 std::unique_ptr<BubbleUi> ExtensionInstalledBubble::BuildBubbleUi() {
   return base::WrapUnique(new ExtensionInstalledBubbleUi(this));
 }