Check the validity of cache_ weak ptr in DoFinishHeaders

net/http/http_cache_transaction.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/http/http_cache_transaction.h"
 
 #include "build/build_config.h"  // For OS_POSIX
 
 #if defined(OS_POSIX)
 #include <unistd.h>
@@ skipping 1815 matching lines @@
 
   entry_ = nullptr;
   if (network_trans_)
     network_trans_.reset();
 
   TransitionToState(STATE_GET_BACKEND);
   return OK;
 }
 
 int HttpCache::Transaction::DoFinishHeaders(int result) {
-  if (!entry_ || result != OK) {
+  if (!cache_.get() || !entry_ || result != OK) {
     TransitionToState(STATE_NONE);
     return result;
   }
 
   TransitionToState(STATE_FINISH_HEADERS_COMPLETE);
 
   // If it was an auth failure or 416, this transaction should continue to be
   // headers_transaction till consumer takes an action, so no need to do
   // anything now.
   if (auth_response_.headers.get() ||
@@ skipping 1283 matching lines @@
 }
 
 void HttpCache::Transaction::TransitionToState(State state) {
   // Ensure that the state is only set once per Do* state.
   DCHECK(in_do_loop_);
   DCHECK_EQ(STATE_UNSET, next_state_) << "Next state is " << state;
   next_state_ = state;
 }
 
 }  // namespace net