[FileAPI] Replace default leveldb::Env with leveldb::MemEnv in tests.

chrome/browser/sync_file_system/local/local_file_sync_service.h

Index: chrome/browser/sync_file_system/local/local_file_sync_service.h
diff --git a/chrome/browser/sync_file_system/local/local_file_sync_service.h b/chrome/browser/sync_file_system/local/local_file_sync_service.h
index fdffa4ac6644afc0c1b00a0cd3bade5e12987f0d..a98e3a3be01ae62aacc42a1dbcb2161b788fea29 100644
--- a/chrome/browser/sync_file_system/local/local_file_sync_service.h
+++ b/chrome/browser/sync_file_system/local/local_file_sync_service.h
@@ -26,6 +26,10 @@ namespace fileapi {
 class FileSystemContext;
 }
 
+namespace leveldb {
+class Env;
+}
+
 namespace webkit_blob {
 class ScopedFile;
 }
@@ -66,7 +70,10 @@ class LocalFileSyncService
                               bool has_pending_changes)>
       HasPendingLocalChangeCallback;
 
-  explicit LocalFileSyncService(Profile* profile);
+  static scoped_ptr<LocalFileSyncService> Create(Profile* profile);
+  static scoped_ptr<LocalFileSyncService> CreateForTesting(
+      Profile* profile,
+      leveldb::Env* env_override);
   virtual ~LocalFileSyncService();
 
   void Shutdown();
@@ -182,6 +189,8 @@ class LocalFileSyncService
     std::set<GURL> disabled_origins_;
   };
 
+  LocalFileSyncService(Profile* profile, leveldb::Env* env_override);
+
   void DidInitializeFileSystemContext(
       const GURL& app_origin,
       fileapi::FileSystemContext* file_system_context,