Add static domain security state generator tool.

net/tools/domain_security_preload_generator/huffman/huffman_node.cc

+// Copyright (c) 2016 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.
+
+#include "net/tools/domain_security_preload_generator/huffman/huffman_node.h"
+
+namespace net {
+
+HuffmanNode::HuffmanNode(uint8_t value,
+                         int count,
+                         std::unique_ptr<HuffmanNode> left,
+                         std::unique_ptr<HuffmanNode> right)
+    : value_(value),
+      count_(count),
+      left_(std::move(left)),
+      right_(std::move(right)) {}
+
+HuffmanNode::~HuffmanNode() {}
+
+bool HuffmanNode::IsLeaf() const {
+  return left_.get() == nullptr && right_.get() == nullptr;
+}
+
+}  // namespace net