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

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

 // Copyright (c) 2012 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/extension_install_dialog_controller.h"
 
 #include "base/bind.h"
 #include "base/logging.h"
 #include "base/memory/ref_counted.h"
 #include "base/message_loop/message_loop.h"
 #include "chrome/browser/extensions/api/experience_sampling_private/experience_sampling.h"
+#include "chrome/browser/extensions/extension_install_prompt_show_params.h"
 #include "chrome/browser/ui/browser.h"
 #include "chrome/browser/ui/browser_finder.h"
 #import "chrome/browser/ui/cocoa/constrained_window/constrained_window_custom_sheet.h"
 #include "chrome/browser/ui/cocoa/constrained_window/constrained_window_custom_window.h"
 #import "chrome/browser/ui/cocoa/extensions/extension_install_view_controller.h"
 #import "chrome/browser/ui/cocoa/extensions/windowed_install_dialog_controller.h"
 #include "chrome/browser/ui/tabs/tab_strip_model.h"
 #include "content/public/browser/web_contents.h"
 
 using extensions::ExperienceSamplingEvent;
 
 namespace {
 
 void ShowExtensionInstallDialogImpl(
-    const ExtensionInstallPrompt::ShowParams& show_params,
+    ExtensionInstallPromptShowParams* show_params,
     ExtensionInstallPrompt::Delegate* delegate,
     scoped_refptr<ExtensionInstallPrompt::Prompt> prompt) {
   // These objects will delete themselves when the dialog closes.
-  if (!show_params.parent_web_contents) {
+  if (!show_params->GetParentWebContents()) {
     new WindowedInstallDialogController(show_params, delegate, prompt);
     return;
   }
 
   new ExtensionInstallDialogController(show_params, delegate, prompt);
 }
 
 }  // namespace
 
 ExtensionInstallDialogController::ExtensionInstallDialogController(
-    const ExtensionInstallPrompt::ShowParams& show_params,
+    ExtensionInstallPromptShowParams* show_params,
     ExtensionInstallPrompt::Delegate* delegate,
     scoped_refptr<ExtensionInstallPrompt::Prompt> prompt)
     : delegate_(delegate) {
   view_controller_.reset([[ExtensionInstallViewController alloc]
-      initWithProfile:show_params.profile
-            navigator:show_params.parent_web_contents
+      initWithProfile:show_params->profile()
+            navigator:show_params->GetParentWebContents()
              delegate:this
                prompt:prompt]);
 
   base::scoped_nsobject<NSWindow> window([[ConstrainedWindowCustomWindow alloc]
       initWithContentRect:[[view_controller_ view] bounds]]);
   [[window contentView] addSubview:[view_controller_ view]];
 
   base::scoped_nsobject<CustomConstrainedWindowSheet> sheet(
       [[CustomConstrainedWindowSheet alloc] initWithCustomWindow:window]);
   constrained_window_.reset(new ConstrainedWindowMac(
-      this, show_params.parent_web_contents, sheet));
+      this, show_params->GetParentWebContents(), sheet));
 
   std::string event_name = ExperienceSamplingEvent::kExtensionInstallDialog;
   event_name.append(ExtensionInstallPrompt::PromptTypeToString(prompt->type()));
   sampling_event_ = ExperienceSamplingEvent::Create(event_name);
 }
 
 ExtensionInstallDialogController::~ExtensionInstallDialogController() {
 }
 
 void ExtensionInstallDialogController::InstallUIProceed() {
@@ skipping 17 matching lines @@
   if (delegate_)
     delegate_->InstallUIAbort(false);
   base::MessageLoop::current()->DeleteSoon(FROM_HERE, this);
 }
 
 // static
 ExtensionInstallPrompt::ShowDialogCallback
 ExtensionInstallPrompt::GetDefaultShowDialogCallback() {
   return base::Bind(&ShowExtensionInstallDialogImpl);
 }