Add woff2 to src/third_party

third_party/woff2/src/round.h

Index: third_party/woff2/src/round.h
diff --git a/third_party/woff2/src/round.h b/third_party/woff2/src/round.h
new file mode 100644
index 0000000000000000000000000000000000000000..abb81f8235d0828712ab2321cb89db2cdeab8725
--- /dev/null
+++ b/third_party/woff2/src/round.h
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+// Copyright 2013 Google Inc. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+// Helper for rounding
+
+#ifndef WOFF2_ROUND_H_
+#define WOFF2_ROUND_H_
+
+#include <limits>
+
+namespace woff2 {
+
+// Round a value up to the nearest multiple of 4. Don't round the value in the
+// case that rounding up overflows.
+template<typename T> T Round4(T value) {
+  if (std::numeric_limits<T>::max() - value < 3) {
+    return value;
+  }
+  return (value + 3) & ~3;
+}
+
+} // namespace woff2
+
+#endif  // WOFF2_ROUND_H_