Fixes for re-enabling more MSVC level 4 warnings: net/ edition

net/cert/test_root_certs_win.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/cert/test_root_certs.h"
 
 #include <windows.h>
 #include <wincrypt.h>
 
 #include "base/basictypes.h"
@@ skipping 142 matching lines @@
     return GetLastError() == CRYPT_E_EXISTS;
   }
 
   empty_ = false;
   return true;
 }
 
 void TestRootCerts::Clear() {
   empty_ = true;
 
-  PCCERT_CONTEXT prev_cert = NULL;
-  while (prev_cert = CertEnumCertificatesInStore(temporary_roots_, NULL))
+  for (PCCERT_CONTEXT prev_cert =
+           CertEnumCertificatesInStore(temporary_roots_, NULL);
+       prev_cert;
+       prev_cert = CertEnumCertificatesInStore(temporary_roots_, NULL))
     CertDeleteCertificateFromStore(prev_cert);
 }
 
 bool TestRootCerts::IsEmpty() const {
   return empty_;
 }
 
 HCERTCHAINENGINE TestRootCerts::GetChainEngine() const {
   if (IsEmpty())
     return NULL;  // Default chain engine will suffice.
@@ skipping 29 matching lines @@
 
 void TestRootCerts::Init() {
   empty_ = true;
   temporary_roots_ = CertOpenStore(
       CERT_STORE_PROV_MEMORY, 0, NULL,
       CERT_STORE_DEFER_CLOSE_UNTIL_LAST_FREE_FLAG, NULL);
   DCHECK(temporary_roots_);
 }
 
 }  // namespace net