Restructure things to fit upcoming diff

tests/Layout-consts-test.js

@@ -0,0 +1,22 @@
+/**
+ * Copyright (c) 2014, Facebook, Inc.
+ * All rights reserved.
+ *
+ * This source code is licensed under the BSD-style license found in the
+ * LICENSE file in the root directory of this source tree. An additional grant
+ * of patent rights can be found in the PATENTS file in the same directory.
+ */
+/* globals layoutTestUtils */
+
+var textSizes = layoutTestUtils.textSizes;
+var preDefinedTextSizes = layoutTestUtils.preDefinedTextSizes;
+
+describe('Layout tests consts', function() {
+  it('keeps browser text measurements in sync with predefined consts', function() {
+    expect(preDefinedTextSizes).toEqual(
+      textSizes,
+      'Looks like browser has updated its text measurements functions. ' +
+      'You need to update `preDefinedTextSizes` in Layout-test-utils.js'
+    );
+  });
+});