Remove remaining calls to deprecated MessageLoop methods on Mac.

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 <utility>
 
 #include "base/bind.h"
 #include "base/callback_helpers.h"
 #include "base/logging.h"
 #include "base/memory/ref_counted.h"
-#include "base/message_loop/message_loop.h"
+#include "base/threading/thread_task_runner_handle.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_dialogs.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/windowed_install_dialog_controller.h"
 #include "chrome/browser/ui/tabs/tab_strip_model.h"
 #include "content/public/browser/web_contents.h"
@@ skipping 67 matching lines @@
   OnPromptButtonClicked(ExtensionInstallPrompt::Result::USER_CANCELED,
                         ExperienceSamplingEvent::kDeny);
 }
 
 void ExtensionInstallDialogController::OnConstrainedWindowClosed(
     ConstrainedWindowMac* window) {
   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);
 }
 
 void ExtensionInstallDialogController::OnPromptButtonClicked(
     ExtensionInstallPrompt::Result result,
     const char* decision_event) {
   if (sampling_event_.get())
     sampling_event_->CreateUserDecisionEvent(decision_event);
   base::ResetAndReturn(&done_callback_).Run(result);
   constrained_window_->CloseWebContentsModalDialog();
 }
 
 // static
 ExtensionInstallPrompt::ShowDialogCallback
 ExtensionInstallPrompt::GetDefaultShowDialogCallback() {
   if (chrome::ToolkitViewsWebUIDialogsEnabled())
     return ExtensionInstallPrompt::GetViewsShowDialogCallback();
   return base::Bind(&ShowExtensionInstallDialogImpl);
 }