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

chrome/browser/ui/views/extensions/extension_install_dialog_view.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_UI_VIEWS_EXTENSIONS_EXTENSION_INSTALL_DIALOG_VIEW_H_
 #define CHROME_BROWSER_UI_VIEWS_EXTENSIONS_EXTENSION_INSTALL_DIALOG_VIEW_H_
 
 #include "chrome/browser/extensions/extension_install_prompt.h"
 #include "ui/gfx/animation/animation_delegate.h"
 #include "ui/gfx/animation/slide_animation.h"
 #include "ui/views/controls/button/button.h"
 #include "ui/views/controls/link_listener.h"
 #include "ui/views/view.h"
 #include "ui/views/window/dialog_delegate.h"
 
 typedef std::vector<base::string16> PermissionDetails;
 class ExpandableContainerView;
+class ExtensionInstallPromptShowParams;
 class Profile;
 
 namespace content {
 class PageNavigator;
 }
 
 namespace extensions {
 class ExperienceSamplingEvent;
 }
 
@@ skipping 239 matching lines @@
   // on whether the details section is expanded).
   views::ImageButton* arrow_toggle_;
 
   // Whether the details section is expanded.
   bool expanded_;
 
   DISALLOW_COPY_AND_ASSIGN(ExpandableContainerView);
 };
 
 void ShowExtensionInstallDialogImpl(
-    const ExtensionInstallPrompt::ShowParams& show_params,
+    ExtensionInstallPromptShowParams* show_params,
     ExtensionInstallPrompt::Delegate* delegate,
     scoped_refptr<ExtensionInstallPrompt::Prompt> prompt);
 
 #endif  // CHROME_BROWSER_UI_VIEWS_EXTENSIONS_EXTENSION_INSTALL_DIALOG_VIEW_H_