Remove dart generator code from json schema compiler.

tools/json_schema_compiler/dart_test/empty_type.idl

Index: tools/json_schema_compiler/dart_test/empty_type.idl
diff --git a/tools/json_schema_compiler/dart_test/empty_type.idl b/tools/json_schema_compiler/dart_test/empty_type.idl
deleted file mode 100644
index 9d7de6f7a70556c9a781e5c6c642bdce59d97c19..0000000000000000000000000000000000000000
--- a/tools/json_schema_compiler/dart_test/empty_type.idl
+++ /dev/null
@@ -1,10 +0,0 @@
-// Copyright (c) 2012 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.
-
-// Namespace-level comment for EmptyType.
-namespace empty_type {
-  // Documentation for EmptyType.
-  dictionary EmptyType {
-  };
-};