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

net/dns/host_resolver.h

 // 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.
 
 #ifndef NET_DNS_HOST_RESOLVER_H_
 #define NET_DNS_HOST_RESOLVER_H_
 
 #include <string>
 
 #include "base/memory/scoped_ptr.h"
@@ skipping 102 matching lines @@
   };
 
   // Opaque type used to cancel a request.
   typedef void* RequestHandle;
 
   // Set Options.max_concurrent_resolves to this to select a default level
   // of concurrency.
   static const size_t kDefaultParallelism = 0;
 
   // Set Options.max_retry_attempts to this to select a default retry value.
-  static const size_t kDefaultRetryAttempts = -1;
+  static const size_t kDefaultRetryAttempts = static_cast<size_t>(-1);
 
   // If any completion callbacks are pending when the resolver is destroyed,
   // the host resolutions are cancelled, and the completion callbacks will not
   // be called.
   virtual ~HostResolver();
 
   // Resolves the given hostname (or IP address literal), filling out the
   // |addresses| object upon success.  The |info.port| parameter will be set as
   // the sin(6)_port field of the sockaddr_in{6} struct.  Returns OK if
   // successful or an error code upon failure.  Returns
@@ skipping 64 matching lines @@
  protected:
   HostResolver();
 
  private:
   DISALLOW_COPY_AND_ASSIGN(HostResolver);
 };
 
 }  // namespace net
 
 #endif  // NET_DNS_HOST_RESOLVER_H_