Remove auto raw pointer deduction from non-linux specific code.

ios/chrome/browser/web/repost_form_tab_helper_unittest.mm

 // Copyright 2017 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/web/repost_form_tab_helper.h"
 
 #import <UIKit/UIKit.h>
 
 #include "base/bind.h"
 #include "base/mac/foundation_util.h"
@@ skipping 32 matching lines @@
 
     web_state_->SetView(view);
     web_state_->SetWebUsageEnabled(true);
 
     RepostFormTabHelper::CreateForWebState(web_state_.get());
   }
 
   // Presents a repost form dialog using RepostFormTabHelperTest.
   void PresentDialog() {
     ASSERT_FALSE(GetAlertController());
-    auto helper = RepostFormTabHelper::FromWebState(web_state_.get());
+    auto* helper = RepostFormTabHelper::FromWebState(web_state_.get());
     helper->PresentDialog(location_, base::Bind(&IgnoreBool));
     ASSERT_TRUE(GetAlertController());
   }
 
   // Return presented view controller as UIAlertController.
   UIAlertController* GetAlertController() const {
     return base::mac::ObjCCastStrict<UIAlertController>(
         view_controller_.presentedViewController);
   }
 
@@ skipping 33 matching lines @@
 }
 
 // Tests that dialog is dismissed after provisional navigation has started.
 TEST_F(RepostFormTabHelperTest, DismissingOnNavigationStart) {
   PresentDialog();
   web_state_->OnProvisionalNavigationStarted(GURL());
   base::test::ios::WaitUntilCondition(^{
     return GetAlertController() != nil;
   });
 }