Make DiskCacheBasedQuicServerInfo release buffers when no longer needed

net/http/disk_cache_based_quic_server_info.cc

 // Copyright 2014 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/http/disk_cache_based_quic_server_info.h"
 
 #include "base/bind.h"
 #include "base/callback.h"
 #include "base/callback_helpers.h"
 #include "base/logging.h"
@@ skipping 271 matching lines @@
 
   return OK;
 }
 
 int DiskCacheBasedQuicServerInfo::DoReadComplete(int rv) {
   if (rv > 0)
     data_.assign(read_buffer_->data(), rv);
   else if (rv < 0)
     RecordQuicServerInfoFailure(READ_FAILURE);
 
+  read_buffer_ = nullptr;
   state_ = WAIT_FOR_DATA_READY_DONE;
   return OK;
 }
 
 int DiskCacheBasedQuicServerInfo::DoWriteComplete(int rv) {
   if (rv < 0)
     RecordQuicServerInfoFailure(WRITE_FAILURE);
+  write_buffer_ = nullptr;
   state_ = SET_DONE;
   return OK;
 }
 
 int DiskCacheBasedQuicServerInfo::DoCreateOrOpenComplete(int rv) {
   if (rv != OK) {
     RecordQuicServerInfoFailure(CREATE_OR_OPEN_FAILURE);
     state_ = SET_DONE;
   } else {
     if (!entry_) {
@@ skipping 119 matching lines @@
   } else if (backend_->GetCacheType() == MEMORY_CACHE) {
     UMA_HISTOGRAM_ENUMERATION("Net.QuicDiskCache.FailureReason.MemoryCache",
                               failure, NUM_OF_FAILURES);
   } else {
     UMA_HISTOGRAM_ENUMERATION("Net.QuicDiskCache.FailureReason.DiskCache",
                               failure, NUM_OF_FAILURES);
   }
 }
 
 }  // namespace net