diff --git a/http2/http2_constants_test_util.cc b/http2/http2_constants_test_util.cc
new file mode 100644
index 0000000..e729890
--- /dev/null
+++ b/http2/http2_constants_test_util.cc
@@ -0,0 +1,84 @@
+// Copyright 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/third_party/quiche/src/http2/http2_constants_test_util.h"
+
+namespace http2 {
+namespace test {
+
+std::vector<Http2ErrorCode> AllHttp2ErrorCodes() {
+  // clang-format off
+  return {
+      Http2ErrorCode::HTTP2_NO_ERROR,
+      Http2ErrorCode::PROTOCOL_ERROR,
+      Http2ErrorCode::INTERNAL_ERROR,
+      Http2ErrorCode::FLOW_CONTROL_ERROR,
+      Http2ErrorCode::SETTINGS_TIMEOUT,
+      Http2ErrorCode::STREAM_CLOSED,
+      Http2ErrorCode::FRAME_SIZE_ERROR,
+      Http2ErrorCode::REFUSED_STREAM,
+      Http2ErrorCode::CANCEL,
+      Http2ErrorCode::COMPRESSION_ERROR,
+      Http2ErrorCode::CONNECT_ERROR,
+      Http2ErrorCode::ENHANCE_YOUR_CALM,
+      Http2ErrorCode::INADEQUATE_SECURITY,
+      Http2ErrorCode::HTTP_1_1_REQUIRED,
+  };
+  // clang-format on
+}
+
+std::vector<Http2SettingsParameter> AllHttp2SettingsParameters() {
+  // clang-format off
+  return {
+      Http2SettingsParameter::HEADER_TABLE_SIZE,
+      Http2SettingsParameter::ENABLE_PUSH,
+      Http2SettingsParameter::MAX_CONCURRENT_STREAMS,
+      Http2SettingsParameter::INITIAL_WINDOW_SIZE,
+      Http2SettingsParameter::MAX_FRAME_SIZE,
+      Http2SettingsParameter::MAX_HEADER_LIST_SIZE,
+  };
+  // clang-format on
+}
+
+// Returns a mask of flags supported for the specified frame type. Returns
+// zero for unknown frame types.
+uint8_t KnownFlagsMaskForFrameType(Http2FrameType type) {
+  switch (type) {
+    case Http2FrameType::DATA:
+      return Http2FrameFlag::END_STREAM | Http2FrameFlag::PADDED;
+    case Http2FrameType::HEADERS:
+      return Http2FrameFlag::END_STREAM | Http2FrameFlag::END_HEADERS |
+             Http2FrameFlag::PADDED | Http2FrameFlag::PRIORITY;
+    case Http2FrameType::PRIORITY:
+      return 0x00;
+    case Http2FrameType::RST_STREAM:
+      return 0x00;
+    case Http2FrameType::SETTINGS:
+      return Http2FrameFlag::ACK;
+    case Http2FrameType::PUSH_PROMISE:
+      return Http2FrameFlag::END_HEADERS | Http2FrameFlag::PADDED;
+    case Http2FrameType::PING:
+      return Http2FrameFlag::ACK;
+    case Http2FrameType::GOAWAY:
+      return 0x00;
+    case Http2FrameType::WINDOW_UPDATE:
+      return 0x00;
+    case Http2FrameType::CONTINUATION:
+      return Http2FrameFlag::END_HEADERS;
+    case Http2FrameType::ALTSVC:
+      return 0x00;
+    default:
+      return 0x00;
+  }
+}
+
+uint8_t InvalidFlagMaskForFrameType(Http2FrameType type) {
+  if (IsSupportedHttp2FrameType(type)) {
+    return ~KnownFlagsMaskForFrameType(type);
+  }
+  return 0x00;
+}
+
+}  // namespace test
+}  // namespace http2