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

chrome/browser/ui/cocoa/extensions/windowed_install_dialog_controller.mm

 // 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.
 
 #import "chrome/browser/ui/cocoa/extensions/windowed_install_dialog_controller.h"
 
 #import "base/mac/sdk_forward_declarations.h"
 #include "base/message_loop/message_loop.h"
 #include "base/strings/sys_string_conversions.h"
+#include "chrome/browser/extensions/extension_install_prompt_show_params.h"
 #include "chrome/browser/profiles/profile.h"
 #import "chrome/browser/ui/cocoa/extensions/extension_install_view_controller.h"
 #include "content/public/browser/web_contents.h"
 #include "ui/base/cocoa/window_size_constants.h"
 
 @interface WindowedInstallController
     : NSWindowController<NSWindowDelegate> {
  @private
   base::scoped_nsobject<ExtensionInstallViewController> installViewController_;
   WindowedInstallDialogController* dialogController_;  // Weak. Owns us.
 }
 
 @property(readonly, nonatomic) ExtensionInstallViewController* viewController;
 
 - (id)initWithProfile:(Profile*)profile
             navigator:(content::PageNavigator*)navigator
              delegate:(WindowedInstallDialogController*)delegate
                prompt:(scoped_refptr<ExtensionInstallPrompt::Prompt>)prompt;
 
 @end
 
 WindowedInstallDialogController::WindowedInstallDialogController(
-    const ExtensionInstallPrompt::ShowParams& show_params,
+    ExtensionInstallPromptShowParams* show_params,
     ExtensionInstallPrompt::Delegate* delegate,
     scoped_refptr<ExtensionInstallPrompt::Prompt> prompt)
     : delegate_(delegate) {
   install_controller_.reset([[WindowedInstallController alloc]
-      initWithProfile:show_params.profile
-            navigator:show_params.parent_web_contents
+      initWithProfile:show_params->profile()
+            navigator:show_params->GetParentWebContents()
              delegate:this
                prompt:prompt]);
   [[install_controller_ window] makeKeyAndOrderFront:nil];
 }
 
 WindowedInstallDialogController::~WindowedInstallDialogController() {
   DCHECK(!install_controller_);
   DCHECK(!delegate_);
 }
 
@@ skipping 65 matching lines @@
 - (ExtensionInstallViewController*)viewController {
   return installViewController_;
 }
 
 - (void)windowWillClose:(NSNotification*)notification {
   [[self window] setDelegate:nil];
   dialogController_->OnWindowClosing();
 }
 
 @end