Coverity: Fix leak in SessionBackend::OpenAndWriteHeader on error conditions.

chrome/browser/sessions/session_backend.cc

 // Copyright (c) 2010 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 "chrome/browser/sessions/session_backend.h"
 
 #include <limits>
 
 #include "base/file_util.h"
 #include "base/histogram.h"
@@ skipping 334 matching lines @@
     if (current_session_file_->Truncate(sizeof_header()) != sizeof_header())
       current_session_file_.reset(NULL);
   }
   if (!current_session_file_.get())
     current_session_file_.reset(OpenAndWriteHeader(GetCurrentSessionPath()));
   empty_file_ = true;
 }
 
 net::FileStream* SessionBackend::OpenAndWriteHeader(const FilePath& path) {
   DCHECK(!path.empty());
-  net::FileStream* file = new net::FileStream();
+  scoped_ptr<net::FileStream> file(new net::FileStream());
   file->Open(path, base::PLATFORM_FILE_CREATE_ALWAYS |
              base::PLATFORM_FILE_WRITE | base::PLATFORM_FILE_EXCLUSIVE_WRITE |
              base::PLATFORM_FILE_EXCLUSIVE_READ);
   if (!file->IsOpen())
     return NULL;
   int32 header[2];
   header[0] = kFileSignature;
   header[1] = kFileCurrentVersion;
   int wrote = file->Write(reinterpret_cast<char*>(&header),
                           sizeof(header), NULL);
   if (wrote != sizeof_header())
     return NULL;
-  return file;
+  return file.release();
 }
 
 FilePath SessionBackend::GetLastSessionPath() {
   FilePath path = path_to_dir_;
   if (type_ == BaseSessionService::TAB_RESTORE)
     path = path.AppendASCII(kLastTabSessionFileName);
   else
     path = path.AppendASCII(kLastSessionFileName);
   return path;
 }
 
 FilePath SessionBackend::GetCurrentSessionPath() {
   FilePath path = path_to_dir_;
   if (type_ == BaseSessionService::TAB_RESTORE)
     path = path.AppendASCII(kCurrentTabSessionFileName);
   else
     path = path.AppendASCII(kCurrentSessionFileName);
   return path;
 }