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

chrome/browser/ui/views/extensions/extension_install_dialog_view.h

Index: chrome/browser/ui/views/extensions/extension_install_dialog_view.h
diff --git a/chrome/browser/ui/views/extensions/extension_install_dialog_view.h b/chrome/browser/ui/views/extensions/extension_install_dialog_view.h
index ee88a13d1804cc0631198c2e14527be64d18dfdb..6a1b9b90d024f126d6b6c02bc09bde3b568dab4d 100644
--- a/chrome/browser/ui/views/extensions/extension_install_dialog_view.h
+++ b/chrome/browser/ui/views/extensions/extension_install_dialog_view.h
@@ -15,6 +15,7 @@
 
 typedef std::vector<base::string16> PermissionDetails;
 class ExpandableContainerView;
+class ExtensionInstallPromptShowParams;
 class Profile;
 
 namespace content {
@@ -277,7 +278,7 @@ class ExpandableContainerView : public views::View,
 };
 
 void ShowExtensionInstallDialogImpl(
-    const ExtensionInstallPrompt::ShowParams& show_params,
+    ExtensionInstallPromptShowParams* show_params,
     ExtensionInstallPrompt::Delegate* delegate,
     scoped_refptr<ExtensionInstallPrompt::Prompt> prompt);