Add QuicStringPiece which is actually StringPiece.

net/quic/platform/impl/quic_hostname_utils_impl.cc

 // Copyright (c) 2013 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/quic/platform/impl/quic_hostname_utils_impl.h"
 
 #include "net/base/url_util.h"
 #include "url/gurl.h"
 #include "url/url_canon.h"
 
-using base::StringPiece;
 using std::string;
 
 namespace net {
 
 // static
-bool QuicHostnameUtilsImpl::IsValidSNI(StringPiece sni) {
+bool QuicHostnameUtilsImpl::IsValidSNI(QuicStringPiece sni) {
   // TODO(rtenneti): Support RFC2396 hostname.
   // NOTE: Microsoft does NOT enforce this spec, so if we throw away hostnames
   // based on the above spec, we may be losing some hostnames that windows
   // would consider valid. By far the most common hostname character NOT
   // accepted by the above spec is '_'.
   url::CanonHostInfo host_info;
   string canonicalized_host(CanonicalizeHost(sni.as_string(), &host_info));
   return !host_info.IsIPAddress() &&
          IsCanonicalizedHostCompliant(canonicalized_host) &&
          sni.find_last_of('.') != string::npos;
@@ skipping 28 matching lines @@
   if (!url.is_valid()) {
     *out = QuicServerId();
     return;
   }
   *out = QuicServerId(HostPortPair::FromURL(url), url.path_piece() == "/private"
                                                       ? PRIVACY_MODE_ENABLED
                                                       : PRIVACY_MODE_DISABLED);
 }
 
 }  // namespace net