Cleanup: Remove unused variables in chrome/ found by Scythe.

chrome/browser/sync_file_system/drive_backend/drive_backend_constants.cc

 // Copyright 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 "chrome/browser/sync_file_system/drive_backend/drive_backend_constants.h"
 
 namespace sync_file_system {
 namespace drive_backend {
 
 const char kSyncRootFolderTitle[] = "Chrome Syncable FileSystem";
-const char kSyncRootFolderTitleDev[] = "Chrome Syncable FileSystem Dev";
 const char kMimeTypeOctetStream[] = "application/octet-stream";
 
 const base::FilePath::CharType kDatabaseName[] =
     FILE_PATH_LITERAL("DriveMetadata_v2");
 
 const char kDatabaseVersionKey[] = "VERSION";
 const int64 kCurrentDatabaseVersion = 3;
 const int64 kDatabaseOnDiskVersion = 4;
 const char kServiceMetadataKey[] = "SERVICE";
 const char kFileMetadataKeyPrefix[] = "FILE: ";
@@ skipping 10 matching lines @@
 const char kDirtyIDKeyPrefix[] = "DIRTY: ";
 const char kDemotedDirtyIDKeyPrefix[] = "DEMOTED_DIRTY: ";
 
 const int kMaxRetry = 5;
 const int64 kListChangesRetryDelaySeconds = 60 * 60;
 
 const int64 kInvalidTrackerID = 0;
 
 }  // namespace drive_backend
 }  // namespace sync_file_system