Remove remaining calls to deprecated MessageLoop methods on Mac.

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"
 
 #include <utility>
 
 #import "base/callback_helpers.h"
 #import "base/mac/sdk_forward_declarations.h"
-#include "base/message_loop/message_loop.h"
 #include "base/strings/sys_string_conversions.h"
+#include "base/threading/thread_task_runner_handle.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_;
@@ skipping 26 matching lines @@
   DCHECK(!install_controller_);
   DCHECK(done_callback_.is_null());
 }
 
 void WindowedInstallDialogController::OnWindowClosing() {
   install_controller_.reset();
   if (!done_callback_.is_null()) {
     base::ResetAndReturn(&done_callback_).Run(
         ExtensionInstallPrompt::Result::ABORTED);
   }
-  base::MessageLoop::current()->DeleteSoon(FROM_HERE, this);
+  base::ThreadTaskRunnerHandle::Get()->DeleteSoon(FROM_HERE, this);
 }
 
 ExtensionInstallViewController*
 WindowedInstallDialogController::GetViewController() {
   return [install_controller_ viewController];
 }
 
 void WindowedInstallDialogController::OnOkButtonClicked() {
   base::ResetAndReturn(&done_callback_).Run(
       ExtensionInstallPrompt::Result::ACCEPTED);
@@ skipping 55 matching lines @@
 - (ExtensionInstallViewController*)viewController {
   return installViewController_;
 }
 
 - (void)windowWillClose:(NSNotification*)notification {
   [[self window] setDelegate:nil];
   dialogController_->OnWindowClosing();
 }
 
 @end