Sparse IO: Allow failover to network in debug builds

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 478 matching lines @@
 void SimpleEntryImpl::CancelSparseIO() {
   DCHECK(io_thread_checker_.CalledOnValidThread());
   // TODO(gavinp): Determine if the simple backend should support sparse data.
   NOTIMPLEMENTED();
 }
 
 int SimpleEntryImpl::ReadyForSparseIO(const CompletionCallback& callback) {
   DCHECK(io_thread_checker_.CalledOnValidThread());
   // TODO(gavinp): Determine if the simple backend should support sparse data.
   NOTIMPLEMENTED();
-  return net::ERR_FAILED;
+  return net::ERR_NOT_IMPLEMENTED;
 }
 
 SimpleEntryImpl::~SimpleEntryImpl() {
   DCHECK(io_thread_checker_.CalledOnValidThread());
   DCHECK_EQ(0U, pending_operations_.size());
   DCHECK(state_ == STATE_UNINITIALIZED || state_ == STATE_FAILURE);
   DCHECK(!synchronous_entry_);
   RemoveSelfFromBackend();
   net_log_.EndEvent(net::NetLog::TYPE_SIMPLE_CACHE_ENTRY);
 }
@@ skipping 685 matching lines @@
     } else {
       type = conflicting ? WRITE_FOLLOWS_CONFLICTING_WRITE
                          : WRITE_FOLLOWS_NON_CONFLICTING_WRITE;
     }
   }
   UMA_HISTOGRAM_ENUMERATION(
       "SimpleCache.WriteDependencyType", type, WRITE_DEPENDENCY_TYPE_MAX);
 }
 
 }  // namespace disk_cache