Implement basic classes for HPACK (HTTP/2 compression)

net/spdy/hpack_string_util.cc

+// Copyright (c) 2014 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/spdy/hpack_string_util.h"
+
+#include "base/basictypes.h"
+
+namespace net {
+
+bool StringPiecesEqualConstantTime(base::StringPiece str1,
+                                   base::StringPiece str2) {
+  size_t size = str1.size();
+  if (str2.size() != size)
+    return false;
+
+  uint8 x = 0;
+  for (size_t i = 0; i < size; ++i) {
+    x |= str1[i] ^ str2[i];
+  }
+  return x == 0;
+}
+
+}  // namespace net