Fix crash when user closes window prior to the "Confirm Install" prompt showing

chrome/browser/extensions/external_install_error.h

 // Copyright 2014 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_EXTENSIONS_EXTERNAL_INSTALL_ERROR_H_
 #define CHROME_BROWSER_EXTENSIONS_EXTERNAL_INSTALL_ERROR_H_
 
 #include <string>
 
 #include "base/macros.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/memory/weak_ptr.h"
 #include "chrome/browser/extensions/extension_install_prompt.h"
 #include "chrome/browser/extensions/webstore_data_fetcher_delegate.h"
 
 class Browser;
+class ExtensionInstallPromptShowParams;
 class ExtensionInstallUI;
 class GlobalError;
 class GlobalErrorService;
 
 namespace content {
 class BrowserContext;
 }
 
 namespace extensions {
 class Extension;
@@ skipping 42 matching lines @@
   void OnWebstoreRequestFailure() override;
   void OnWebstoreResponseParseSuccess(
       scoped_ptr<base::DictionaryValue> webstore_data) override;
   void OnWebstoreResponseParseFailure(const std::string& error) override;
 
   // Called when data fetching has completed (either successfully or not).
   void OnFetchComplete();
 
   // Called when the dialog has been successfully populated, and is ready to be
   // shown.
-  void OnDialogReady(const ExtensionInstallPrompt::ShowParams& show_params,
+  void OnDialogReady(ExtensionInstallPromptShowParams* show_params,
                      ExtensionInstallPrompt::Delegate* prompt_delegate,
                      scoped_refptr<ExtensionInstallPrompt::Prompt> prompt);
 
   // The associated BrowserContext.
   content::BrowserContext* browser_context_;
 
   // The id of the external extension.
   std::string extension_id_;
 
   // The type of alert to show the user.
   AlertType alert_type_;
 
   // The owning ExternalInstallManager.
   ExternalInstallManager* manager_;
 
   // The associated GlobalErrorService.
   GlobalErrorService* error_service_;
 
   // The UI for showing the error.
   scoped_ptr<ExtensionInstallPrompt> install_ui_;
+  scoped_ptr<ExtensionInstallPromptShowParams> install_ui_show_params_;
   scoped_refptr<ExtensionInstallPrompt::Prompt> prompt_;
 
   // The UI for the given error, which will take the form of either a menu
   // alert or a bubble alert (depending on the |alert_type_|.
   scoped_ptr<GlobalError> global_error_;
 
   // The WebstoreDataFetcher to use in order to populate the error with webstore
   // information of the extension.
   scoped_ptr<WebstoreDataFetcher> webstore_data_fetcher_;
 
   base::WeakPtrFactory<ExternalInstallError> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(ExternalInstallError);
 };
 
 }  // namespace extensions
 
 #endif  // CHROME_BROWSER_EXTENSIONS_EXTERNAL_INSTALL_ERROR_H_