[SyncFS] Use dedicated temporary directory in LocalFileChangeTrackerTest

chrome/browser/sync_file_system/local/local_file_change_tracker_unittest.cc

Index: chrome/browser/sync_file_system/local/local_file_change_tracker_unittest.cc
diff --git a/chrome/browser/sync_file_system/local/local_file_change_tracker_unittest.cc b/chrome/browser/sync_file_system/local/local_file_change_tracker_unittest.cc
index a1f860d5333542843efb940a3713154c732a1503..c1aa548de6ff48b11c36a5905a9c37c8d8758591 100644
--- a/chrome/browser/sync_file_system/local/local_file_change_tracker_unittest.cc
+++ b/chrome/browser/sync_file_system/local/local_file_change_tracker_unittest.cc
@@ -45,8 +45,9 @@ class LocalFileChangeTrackerTest : public testing::Test {
   virtual void SetUp() OVERRIDE {
     file_system_.SetUp(CannedSyncableFileSystem::QUOTA_ENABLED);
 
+    ASSERT_TRUE(base_dir_.CreateUniqueTempDir());
     sync_context_ =
-        new LocalFileSyncContext(base::FilePath(),
+        new LocalFileSyncContext(base_dir_.path(),
                                  in_memory_env_.get(),
                                  base::ThreadTaskRunnerHandle::Get().get(),
                                  base::ThreadTaskRunnerHandle::Get().get());
@@ -110,6 +111,7 @@ class LocalFileChangeTrackerTest : public testing::Test {
   }
 
   base::MessageLoopForIO message_loop_;
+  base::ScopedTempDir base_dir_;
   scoped_ptr<leveldb::Env> in_memory_env_;
   CannedSyncableFileSystem file_system_;