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

webkit/browser/fileapi/sandbox_directory_database_unittest.cc

Index: webkit/browser/fileapi/sandbox_directory_database_unittest.cc
diff --git a/webkit/browser/fileapi/sandbox_directory_database_unittest.cc b/webkit/browser/fileapi/sandbox_directory_database_unittest.cc
index 9b5e9ba6bb290c507233cb7621bf97a1e79b83c6..0201987593b7ae7df4c49e7db6ad00bf1de264df 100644
--- a/webkit/browser/fileapi/sandbox_directory_database_unittest.cc
+++ b/webkit/browser/fileapi/sandbox_directory_database_unittest.cc
@@ -44,7 +44,7 @@ class SandboxDirectoryDatabaseTest : public testing::Test {
     // Call CloseDatabase() to avoid having multiple database instances for
     // single directory at once.
     CloseDatabase();
-    db_.reset(new SandboxDirectoryDatabase(path()));
+    db_.reset(new SandboxDirectoryDatabase(path(), NULL));
   }
 
   void CloseDatabase() {
@@ -98,7 +98,7 @@ class SandboxDirectoryDatabaseTest : public testing::Test {
     db_.reset();
     ASSERT_TRUE(base::DeleteFile(path(), true /* recursive */));
     ASSERT_TRUE(base::CreateDirectory(path()));
-    db_.reset(new SandboxDirectoryDatabase(path()));
+    db_.reset(new SandboxDirectoryDatabase(path(), NULL));
   }
 
   bool RepairDatabase() {