Use string(StringPiece) instead of StringPiece::as_string().

net/spdy/spdy_header_block.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/spdy/spdy_header_block.h"
 
 #include <string.h>
 
 #include <algorithm>
 #include <utility>
@@ skipping 200 matching lines @@
     lookup_result_->second =
         HeaderValue(storage_, key_, storage_->Write(value));
   }
   return *this;
 }
 
 string SpdyHeaderBlock::ValueProxy::as_string() const {
   if (lookup_result_ == block_->end()) {
     return "";
   } else {
-    return lookup_result_->second.value().as_string();
+    return std::string(lookup_result_->second.value());
   }
 }
 
 SpdyHeaderBlock::SpdyHeaderBlock() : block_(kInitialMapBuckets) {}
 
 SpdyHeaderBlock::SpdyHeaderBlock(SpdyHeaderBlock&& other) = default;
 
 SpdyHeaderBlock::~SpdyHeaderBlock() {}
 
 SpdyHeaderBlock& SpdyHeaderBlock::operator=(SpdyHeaderBlock&& other) {
@@ skipping 165 matching lines @@
   for (++it; it != fragments.end(); ++it) {
     memcpy(dst, separator.data(), separator.size());
     dst += separator.size();
     memcpy(dst, it->data(), it->size());
     dst += it->size();
   }
   return dst - original_dst;
 }
 
 }  // namespace net