Add support to sha256 hash the downloaded file....

chrome/browser/download/save_file_manager.cc

 // Copyright (c) 2006-2008 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 "build/build_config.h"
 
 #include "chrome/browser/download/save_file_manager.h"
 
 #include "base/file_util.h"
 #include "base/logging.h"
@@ skipping 204 matching lines @@
 
 // The IO thread created |info|, but the file thread (this method) uses it
 // to create a SaveFile which will hold and finally destroy |info|. It will
 // then passes |info| to the UI thread for reporting saving status.
 void SaveFileManager::StartSave(SaveFileCreateInfo* info) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::FILE));
   DCHECK(info);
   SaveFile* save_file = new SaveFile(info);
 
   // TODO(phajdan.jr): We should check the return value and handle errors here.
-  save_file->Initialize();
+  save_file->Initialize(false);  // No need to calculate hash.
 
   DCHECK(!LookupSaveFile(info->save_id));
   save_file_map_[info->save_id] = save_file;
   info->path = save_file->full_path();
 
   BrowserThread::PostTask(
       BrowserThread::UI, FROM_HERE,
       NewRunnableMethod(this, &SaveFileManager::OnStartSave, info));
 }
 
@@ skipping 287 matching lines @@
     SaveFileMap::iterator it = save_file_map_.find(*i);
     if (it != save_file_map_.end()) {
       SaveFile* save_file = it->second;
       DCHECK(!save_file->in_progress());
       file_util::Delete(save_file->full_path(), false);
       delete save_file;
       save_file_map_.erase(it);
     }
   }
 }