Disk cache: Remove all non essential synchronization from the cache destructor.

net/disk_cache/storage_block-inl.h

-// Copyright (c) 2011 The Chromium Authors. All rights reserved.
+// 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.
 
 #ifndef NET_DISK_CACHE_STORAGE_BLOCK_INL_H_
 #define NET_DISK_CACHE_STORAGE_BLOCK_INL_H_
 #pragma once
 
 #include "net/disk_cache/storage_block.h"
 
 #include "base/logging.h"
@@ skipping 70 matching lines @@
     return;
   DCHECK(!modified_);
   data_ = NULL;
 }
 
 template<typename T> void StorageBlock<T>::set_modified() {
   DCHECK(data_);
   modified_ = true;
 }
 
+template<typename T> void StorageBlock<T>::clear_modified() {
+  modified_ = false;
+}
+
 template<typename T> T* StorageBlock<T>::Data() {
   if (!data_)
     AllocateData();
   return data_;
 }
 
 template<typename T> bool StorageBlock<T>::HasData() const {
   return (NULL != data_);
 }
 
@@ skipping 61 matching lines @@
   }
 }
 
 template<typename T> uint32 StorageBlock<T>::CalculateHash() const {
   return Hash(reinterpret_cast<char*>(data_), offsetof(T, self_hash));
 }
 
 }  // namespace disk_cache
 
 #endif  // NET_DISK_CACHE_STORAGE_BLOCK_INL_H_