Only skip updating computed flex basis within the same generation

Summary:
computed flex basis was incorrectly being reused in some circumstances between calls to caluclateLayout

also run format script.

Reviewed By: dshahidehpour

Differential Revision: D4207106

fbshipit-source-id: fc1063ca79ecf75f6101aadded53bca96cb0585d

tests/CSSLayoutRelayoutTest.cpp

@@ -0,0 +1,27 @@
+/**
+ * Copyright (c) 2014-present, 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.
+ */
+
+#include <CSSLayout/CSSLayout.h>
+#include <gtest/gtest.h>
+
+TEST(CSSLayoutTest, dont_cache_computed_flex_basis_between_layouts) {
+  const CSSNodeRef root = CSSNodeNew();
+
+  const CSSNodeRef root_child0 = CSSNodeNew();
+  CSSNodeStyleSetHeight(root_child0, 10);
+  CSSNodeStyleSetFlexBasis(root_child0, 20);
+  CSSNodeInsertChild(root, root_child0, 0);
+
+  CSSNodeCalculateLayout(root, 100, CSSUndefined, CSSDirectionLTR);
+  CSSNodeCalculateLayout(root, 100, 100, CSSDirectionLTR);
+
+  ASSERT_EQ(20, CSSNodeLayoutGetHeight(root_child0));
+
+  CSSNodeFreeRecursive(root);
+}