Migrate StringPiece::AppendToString to StrAppend

net/quic/core/quic_framer_test.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/quic/core/quic_framer.h"
 
 #include <algorithm>
 #include <cstdint>
 #include <map>
 #include <memory>
@@ skipping 229 matching lines @@
 
   bool OnPacketHeader(const QuicPacketHeader& header) override {
     ++packet_count_;
     header_.reset(new QuicPacketHeader(header));
     return accept_packet_;
   }
 
   bool OnStreamFrame(const QuicStreamFrame& frame) override {
     ++frame_count_;
     // Save a copy of the data so it is valid after the packet is processed.
-    string* string_data = new string();
-    StringPiece(frame.data_buffer, frame.data_length)
-        .AppendToString(string_data);
+    string* string_data = new string(frame.data_buffer, frame.data_length);
     stream_data_.push_back(base::WrapUnique(string_data));
     stream_frames_.push_back(base::MakeUnique<QuicStreamFrame>(
         frame.stream_id, frame.fin, frame.offset, *string_data));
     return true;
   }
 
   bool OnAckFrame(const QuicAckFrame& frame) override {
     ++frame_count_;
     ack_frames_.push_back(base::MakeUnique<QuicAckFrame>(frame));
     return true;
@@ skipping 3925 matching lines @@
     'o',  ' ',  'w',  'o',
     'r',  'l',  'd',  '!',
   };
   // clang-format on
 
   QuicFramerFuzzFunc(packet, arraysize(packet));
 }
 
 }  // namespace test
 }  // namespace net