Update from https://crrev.com/316786

net/quic/quic_data_writer.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/quic_data_writer.h"
 
 #include <algorithm>
 #include <limits>
 #include <string>
 
 #include "base/basictypes.h"
 #include "base/logging.h"
 
 using base::StringPiece;
 using std::numeric_limits;
 
 namespace net {
 
-QuicDataWriter::QuicDataWriter(size_t size)
-    : buffer_(new char[size]),
-      capacity_(size),
-      length_(0) {
+QuicDataWriter::QuicDataWriter(size_t size, char* buffer)
+    : buffer_(buffer), capacity_(size), length_(0) {
 }
 
 QuicDataWriter::~QuicDataWriter() {
-  delete[] buffer_;
 }
 
-char* QuicDataWriter::take() {
-  char* rv = buffer_;
-  buffer_ = nullptr;
-  capacity_ = 0;
-  length_ = 0;
-  return rv;
+char* QuicDataWriter::data() {
+  return buffer_;
 }
 
 bool QuicDataWriter::WriteUInt8(uint8 value) {
   return WriteBytes(&value, sizeof(value));
 }
 
 bool QuicDataWriter::WriteUInt16(uint16 value) {
   return WriteBytes(&value, sizeof(value));
 }
 
@@ skipping 148 matching lines @@
   DCHECK_LT(offset, capacity_);
   size_t latched_length = length_;
   length_ = offset;
   bool success = WriteUInt48(value);
   DCHECK_LE(length_, latched_length);
   length_ = latched_length;
   return success;
 }
 
 }  // namespace net