Fix Simple Cache race on multiple dooms in flight.

net/disk_cache/simple/simple_entry_impl.cc

 // Copyright (c) 2013 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/disk_cache/simple/simple_entry_impl.h"
 
 #include <algorithm>
 #include <cstring>
 #include <vector>
 
@@ skipping 250 matching lines @@
   return ret_value;
 }
 
 int SimpleEntryImpl::DoomEntry(const CompletionCallback& callback) {
   if (doomed_)
     return net::OK;
   net_log_.AddEvent(net::NetLog::TYPE_SIMPLE_CACHE_ENTRY_DOOM_CALL);
   net_log_.AddEvent(net::NetLog::TYPE_SIMPLE_CACHE_ENTRY_DOOM_BEGIN);
 
   MarkAsDoomed();
+  if (backend_.get())
+    backend_->OnDoomStart(entry_hash_);
   pending_operations_.push(SimpleEntryOperation::DoomOperation(this, callback));
   RunNextOperationIfNeeded();
   return net::ERR_IO_PENDING;
 }
 
 void SimpleEntryImpl::SetKey(const std::string& key) {
   key_ = key;
   net_log_.AddEvent(net::NetLog::TYPE_SIMPLE_CACHE_ENTRY_SET_KEY,
       net::NetLog::StringCallback("key", &key));
 }
@@ skipping 629 matching lines @@
   Closure reply = base::Bind(&SimpleEntryImpl::WriteOperationComplete,
                              this,
                              stream_index,
                              callback,
                              base::Passed(&entry_stat),
                              base::Passed(&result));
   worker_pool_->PostTaskAndReply(FROM_HERE, task, reply);
 }
 
 void SimpleEntryImpl::DoomEntryInternal(const CompletionCallback& callback) {
-  if (backend_)
-    backend_->OnDoomStart(entry_hash_);
   PostTaskAndReplyWithResult(
       worker_pool_, FROM_HERE,
       base::Bind(&SimpleSynchronousEntry::DoomEntry, path_, key_, entry_hash_),
       base::Bind(&SimpleEntryImpl::DoomOperationComplete, this, callback,
                  state_));
   state_ = STATE_IO_PENDING;
 }
 
 void SimpleEntryImpl::CreationOperationComplete(
     const CompletionCallback& completion_callback,
@@ skipping 309 matching lines @@
       type = conflicting ? WRITE_FOLLOWS_CONFLICTING_WRITE
                          : WRITE_FOLLOWS_NON_CONFLICTING_WRITE;
     }
   }
   SIMPLE_CACHE_UMA(ENUMERATION,
                    "WriteDependencyType", cache_type_,
                    type, WRITE_DEPENDENCY_TYPE_MAX);
 }
 
 }  // namespace disk_cache