Remove the WARNING security level.

ios/web/net/request_tracker_impl.mm

 // Copyright 2014 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 "ios/web/net/request_tracker_impl.h"
 
 #include <pthread.h>
 #include <stddef.h>
 #include <stdint.h>
 
@@ skipping 301 matching lines @@
   NSString* sslInfo = @"";
   if (sslInfo_.is_valid()) {
     switch (status_.security_style) {
       case web::SECURITY_STYLE_UNKNOWN:
       case web::SECURITY_STYLE_UNAUTHENTICATED:
         sslInfo = @"Unexpected SSL state ";
         break;
       case web::SECURITY_STYLE_AUTHENTICATION_BROKEN:
         sslInfo = @"Not secure ";
         break;
-      case web::SECURITY_STYLE_WARNING:
-        sslInfo = @"Security warning";
-        break;
       case web::SECURITY_STYLE_AUTHENTICATED:
         if (status_.content_status ==
             web::SSLStatus::DISPLAYED_INSECURE_CONTENT)
           sslInfo = @"Mixed ";
         else
           sslInfo = @"Secure ";
         break;
     }
   }
 
@@ skipping 970 matching lines @@
         }));
   }
 }
 
 void RequestTrackerImpl::SetCertificatePolicyCacheForTest(
     web::CertificatePolicyCache* cache) {
   policy_cache_ = cache;
 }
 
 }  // namespace web