Add static domain security state generator tool.

net/tools/domain_security_preload_generator/bit_writer.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/bit_writer.h"
+
+#include "base/logging.h"
+
+namespace net {
+
+BitWriter::BitWriter() : current_byte_(0), used_(0), position_(0) {}
+
+BitWriter::~BitWriter() {}
+
+void BitWriter::WriteBits(uint32_t bits, uint8_t number_of_bits) {
+  CHECK(number_of_bits <= 32);
+  for (uint8_t i = 1; i <= number_of_bits; i++) {
+    uint8_t bit = 1 & (bits >> (number_of_bits - i));
+    WriteBit(bit);
+  }
+}
+
+void BitWriter::WriteBit(uint8_t bit) {
+  current_byte_ |= bit << (7 - used_);
+  used_++;
+  position_++;
+
+  if (used_ == 8) {
+    Close();
+  }
+}
+
+void BitWriter::Close() {
+  bytes_.push_back(current_byte_);
+
+  used_ = 0;
+  current_byte_ = 0;
+}
+
+uint8_t BitWriter::BitLength(uint32_t input) const {
+  uint8_t number_of_bits = 0;
+  while (input != 0) {
+    number_of_bits++;
+    input >>= 1;
+  }
+  return number_of_bits;
+}
+
+}  // namespace net