Update from https://crrev.com/305340

net/dns/host_resolver_impl.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 "net/dns/host_resolver_impl.h"
 
 #if defined(OS_WIN)
 #include <Winsock2.h>
 #elif defined(OS_POSIX)
 #include <netdb.h>
@@ skipping 282 matching lines @@
 
   dict->SetInteger("net_error", net_error);
 
   if (os_error) {
     dict->SetInteger("os_error", os_error);
 #if defined(OS_POSIX)
     dict->SetString("os_error_string", gai_strerror(os_error));
 #elif defined(OS_WIN)
     // Map the error code to a human-readable string.
     LPWSTR error_string = NULL;
-    int size = FormatMessage(FORMAT_MESSAGE_ALLOCATE_BUFFER |
-                             FORMAT_MESSAGE_FROM_SYSTEM,
-                             0,  // Use the internal message table.
-                             os_error,
-                             0,  // Use default language.
-                             (LPWSTR)&error_string,
-                             0,  // Buffer size.
-                             0);  // Arguments (unused).
+    FormatMessage(FORMAT_MESSAGE_ALLOCATE_BUFFER | FORMAT_MESSAGE_FROM_SYSTEM,
+                  0,  // Use the internal message table.
+                  os_error,
+                  0,  // Use default language.
+                  (LPWSTR)&error_string,
+                  0,  // Buffer size.
+                  0);  // Arguments (unused).
     dict->SetString("os_error_string", base::WideToUTF8(error_string));
     LocalFree(error_string);
 #endif
   }
 
   return dict;
 }
 
 // Creates NetLog parameters when the DnsTask failed.
 base::Value* NetLogDnsTaskFailedCallback(int net_error,
@@ skipping 2008 matching lines @@
     dns_client_->SetConfig(dns_config);
     num_dns_failures_ = 0;
     if (dns_client_->GetConfig())
       UMA_HISTOGRAM_BOOLEAN("AsyncDNS.DnsClientEnabled", true);
   }
 
   AbortDnsTasks();
 }
 
 }  // namespace net