Remove remaining calls to deprecated MessageLoop methods on Mac.

ios/chrome/browser/passwords/credential_manager.mm

 // Copyright 2015 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 "ios/chrome/browser/passwords/credential_manager.h"
 
 #include <utility>
 
 #include "base/ios/ios_util.h"
 #import "base/ios/weak_nsobject.h"
 #include "base/mac/bind_objc_block.h"
 #include "base/memory/scoped_vector.h"
-#include "base/message_loop/message_loop.h"
 #include "base/strings/sys_string_conversions.h"
+#include "base/threading/thread_task_runner_handle.h"
 #include "components/password_manager/core/browser/password_store_consumer.h"
 #include "components/password_manager/core/common/credential_manager_types.h"
 #include "components/password_manager/core/common/password_manager_pref_names.h"
 #import "ios/chrome/browser/passwords/js_credential_manager.h"
 #import "ios/web/public/url_scheme_util.h"
 #include "ios/web/public/web_state/credential.h"
 #include "ios/web/public/web_state/url_verification_constants.h"
 #include "ios/web/public/web_state/web_state.h"
 #include "url/origin.h"
 
@@ skipping 93 matching lines @@
   // function will attempt to retrieve a Credential from the PasswordStore that
   // meets the specified parameters and, if successful, send it back to the page
   // via SendCredentialByID.
   DCHECK_GE(request_id, 0);
   password_manager::PasswordStore* store = GetPasswordStore();
 
   // If there's an outstanding request, or the PasswordStore isn't loaded yet,
   // the request should fail outright and the JS Promise should be rejected
   // with an appropriate error.
   if (pending_request_ || !store) {
-    base::MessageLoop::current()->PostTask(
+    base::ThreadTaskRunnerHandle::Get()->PostTask(
         FROM_HERE,
         base::Bind(&CredentialManager::RejectPromise,
                    weak_factory_.GetWeakPtr(), request_id,
                    pending_request_ ? ERROR_TYPE_PENDING_REQUEST
                                     : ERROR_TYPE_PASSWORD_STORE_UNAVAILABLE));
     return;
   }
 
   // If the page requested a zero-click credential -- one that can be returned
   // without first asking the user -- and if zero-click isn't currently
   // available, send back an empty credential.
   if (zero_click_only && !IsZeroClickAllowed()) {
-    base::MessageLoop::current()->PostTask(
+    base::ThreadTaskRunnerHandle::Get()->PostTask(
         FROM_HERE, base::Bind(&CredentialManager::SendCredentialByID,
                               weak_factory_.GetWeakPtr(), request_id,
                               password_manager::CredentialInfo()));
     return;
   }
 
   // If the page origin is untrusted, the request should be rejected.
   GURL page_url;
   if (!GetUrlWithAbsoluteTrust(&page_url)) {
     RejectPromise(request_id, ERROR_TYPE_SECURITY_ERROR_UNTRUSTED_ORIGIN);
@@ skipping 225 matching lines @@
 bool CredentialManager::GetUrlWithAbsoluteTrust(GURL* page_url) {
   web::URLVerificationTrustLevel trust_level =
       web::URLVerificationTrustLevel::kNone;
   const GURL possibly_untrusted_url(web_state()->GetCurrentURL(&trust_level));
   if (trust_level == web::URLVerificationTrustLevel::kAbsolute) {
     *page_url = possibly_untrusted_url;
     return true;
   }
   return false;
 }