Remove use of deprecated MessageLoop methods in chrome/.

chrome/browser/extensions/api/identity/web_auth_flow.cc

 // 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.
 
 #include "chrome/browser/extensions/api/identity/web_auth_flow.h"
 
 #include <utility>
 
 #include "base/base64.h"
 #include "base/location.h"
-#include "base/message_loop/message_loop.h"
+#include "base/single_thread_task_runner.h"
 #include "base/strings/string_util.h"
 #include "base/strings/utf_string_conversions.h"
+#include "base/threading/thread_task_runner_handle.h"
 #include "base/trace_event/trace_event.h"
 #include "chrome/browser/extensions/component_loader.h"
 #include "chrome/browser/extensions/extension_service.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/common/extensions/api/identity_private.h"
 #include "chrome/common/extensions/extension_constants.h"
 #include "components/guest_view/browser/guest_view_base.h"
 #include "content/public/browser/navigation_details.h"
 #include "content/public/browser/navigation_entry.h"
 #include "content/public/browser/notification_details.h"
@@ skipping 79 matching lines @@
         IDR_IDENTITY_API_SCOPE_APPROVAL_MANIFEST,
         base::FilePath(FILE_PATH_LITERAL("identity_scope_approval_dialog")));
   }
 
   EventRouter::Get(profile_)->DispatchEventWithLazyListener(
       extension_misc::kIdentityApiUiAppId, std::move(event));
 }
 
 void WebAuthFlow::DetachDelegateAndDelete() {
   delegate_ = NULL;
-  base::MessageLoop::current()->DeleteSoon(FROM_HERE, this);
+  base::ThreadTaskRunnerHandle::Get()->DeleteSoon(FROM_HERE, this);
 }
 
 void WebAuthFlow::OnAppWindowAdded(AppWindow* app_window) {
   if (app_window->window_key() == app_window_key_ &&
       app_window->extension_id() == extension_misc::kIdentityApiUiAppId) {
     app_window_ = app_window;
     WebContentsObserver::Observe(app_window->web_contents());
 
     registrar_.Add(
         this,
@@ skipping 100 matching lines @@
 }
 
 void WebAuthFlow::DidNavigateMainFrame(
     const content::LoadCommittedDetails& details,
     const content::FrameNavigateParams& params) {
   if (delegate_ && details.http_status_code >= 400)
     delegate_->OnAuthFlowFailure(LOAD_FAILED);
 }
 
 }  // namespace extensions