[SyncFS] Use dedicated temporary directory in LocalFileChangeTrackerTest

chrome/browser/sync_file_system/local/local_file_sync_context.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/local/local_file_sync_context.h"
 
 #include "base/bind.h"
 #include "base/file_util.h"
 #include "base/location.h"
 #include "base/single_thread_task_runner.h"
@@ skipping 38 matching lines @@
     leveldb::Env* env_override,
     base::SingleThreadTaskRunner* ui_task_runner,
     base::SingleThreadTaskRunner* io_task_runner)
     : local_base_path_(base_path.Append(FILE_PATH_LITERAL("local"))),
       env_override_(env_override),
       ui_task_runner_(ui_task_runner),
       io_task_runner_(io_task_runner),
       shutdown_on_ui_(false),
       shutdown_on_io_(false),
       mock_notify_changes_duration_in_sec_(-1) {
+  DCHECK(base_path.IsAbsolute());
   DCHECK(ui_task_runner_->RunsTasksOnCurrentThread());
 }
 
 void LocalFileSyncContext::MaybeInitializeFileSystemContext(
     const GURL& source_url,
     FileSystemContext* file_system_context,
     const SyncStatusCallback& callback) {
   DCHECK(ui_task_runner_->RunsTasksOnCurrentThread());
   if (ContainsKey(file_system_contexts_, file_system_context)) {
     // The context has been already initialized. Just dispatch the callback
@@ skipping 930 matching lines @@
     return;
   }
 
   FileSystemURL url_for_sync = CreateSyncableFileSystemURLForSync(
       file_system_context, dest_url);
   file_system_context->operation_runner()->CopyInForeignFile(
       local_path, url_for_sync, callback);
 }
 
 }  // namespace sync_file_system