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

chrome/browser/extensions/extension_install_prompt.h

Index: chrome/browser/extensions/extension_install_prompt.h
diff --git a/chrome/browser/extensions/extension_install_prompt.h b/chrome/browser/extensions/extension_install_prompt.h
index dca96db147899d21778338bf474598c78a85bccd..f4a87e5e8b70b40853edddc693f7a43522b2d281 100644
--- a/chrome/browser/extensions/extension_install_prompt.h
+++ b/chrome/browser/extensions/extension_install_prompt.h
@@ -22,6 +22,7 @@
 #include "ui/gfx/image/image_skia.h"
 #include "ui/gfx/native_widget_types.h"
 
+class ExtensionInstallPromptShowParams;
 class Profile;
 
 namespace base {
@@ -279,23 +280,7 @@ class ExtensionInstallPrompt
     virtual ~Delegate() {}
   };
 
-  // Parameters to show a prompt dialog. Two sets of the
-  // parameters are supported: either use a parent WebContents or use a
-  // parent NativeWindow + a Profile.
-  struct ShowParams {
-    explicit ShowParams(content::WebContents* contents);
-    ShowParams(Profile* profile, gfx::NativeWindow window);
-
-    Profile* profile;
-
-    // Parent web contents of the install UI dialog. This can be NULL.
-    content::WebContents* parent_web_contents;
-
-    // NativeWindow parent.
-    gfx::NativeWindow parent_window;
-  };
-
-  typedef base::Callback<void(const ExtensionInstallPrompt::ShowParams&,
+  typedef base::Callback<void(ExtensionInstallPromptShowParams*,
                               ExtensionInstallPrompt::Delegate*,
                               scoped_refptr<ExtensionInstallPrompt::Prompt>)>
       ShowDialogCallback;
@@ -328,10 +313,6 @@ class ExtensionInstallPrompt
     return install_ui_.get();
   }
 
-  content::WebContents* parent_web_contents() const {
-    return show_params_.parent_web_contents;
-  }
-
   // This is called by the bundle installer to verify whether the bundle
   // should be installed.
   //
@@ -462,7 +443,7 @@ class ExtensionInstallPrompt
   scoped_ptr<extensions::ExtensionInstallUI> install_ui_;
 
   // Parameters to show the confirmation UI.
-  ShowParams show_params_;
+  scoped_ptr<ExtensionInstallPromptShowParams> show_params_;
 
   // The delegate we will call Proceed/Abort on after confirmation UI.
   Delegate* delegate_;