diff --git a/http2/http2_structures_test_util.cc b/http2/http2_structures_test_util.cc
new file mode 100644
index 0000000..4a1a74d
--- /dev/null
+++ b/http2/http2_structures_test_util.cc
@@ -0,0 +1,109 @@
+// 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_structures_test_util.h"
+
+#include <cstdint>
+
+#include "net/third_party/quiche/src/http2/http2_constants.h"
+#include "net/third_party/quiche/src/http2/http2_constants_test_util.h"
+#include "net/third_party/quiche/src/http2/http2_structures.h"
+#include "net/third_party/quiche/src/http2/test_tools/http2_random.h"
+
+namespace http2 {
+namespace test {
+
+void Randomize(Http2FrameHeader* p, Http2Random* rng) {
+  p->payload_length = rng->Rand32() & 0xffffff;
+  p->type = static_cast<Http2FrameType>(rng->Rand8());
+  p->flags = static_cast<Http2FrameFlag>(rng->Rand8());
+  p->stream_id = rng->Rand32() & StreamIdMask();
+}
+void Randomize(Http2PriorityFields* p, Http2Random* rng) {
+  p->stream_dependency = rng->Rand32() & StreamIdMask();
+  p->weight = rng->Rand8() + 1;
+  p->is_exclusive = rng->OneIn(2);
+}
+void Randomize(Http2RstStreamFields* p, Http2Random* rng) {
+  p->error_code = static_cast<Http2ErrorCode>(rng->Rand32());
+}
+void Randomize(Http2SettingFields* p, Http2Random* rng) {
+  p->parameter = static_cast<Http2SettingsParameter>(rng->Rand16());
+  p->value = rng->Rand32();
+}
+void Randomize(Http2PushPromiseFields* p, Http2Random* rng) {
+  p->promised_stream_id = rng->Rand32() & StreamIdMask();
+}
+void Randomize(Http2PingFields* p, Http2Random* rng) {
+  for (int ndx = 0; ndx < 8; ++ndx) {
+    p->opaque_bytes[ndx] = rng->Rand8();
+  }
+}
+void Randomize(Http2GoAwayFields* p, Http2Random* rng) {
+  p->last_stream_id = rng->Rand32() & StreamIdMask();
+  p->error_code = static_cast<Http2ErrorCode>(rng->Rand32());
+}
+void Randomize(Http2WindowUpdateFields* p, Http2Random* rng) {
+  p->window_size_increment = rng->Rand32() & 0x7fffffff;
+}
+void Randomize(Http2AltSvcFields* p, Http2Random* rng) {
+  p->origin_length = rng->Rand16();
+}
+
+void ScrubFlagsOfHeader(Http2FrameHeader* header) {
+  uint8_t invalid_mask = InvalidFlagMaskForFrameType(header->type);
+  uint8_t keep_mask = ~invalid_mask;
+  header->RetainFlags(keep_mask);
+}
+
+bool FrameIsPadded(const Http2FrameHeader& header) {
+  switch (header.type) {
+    case Http2FrameType::DATA:
+    case Http2FrameType::HEADERS:
+    case Http2FrameType::PUSH_PROMISE:
+      return header.IsPadded();
+    default:
+      return false;
+  }
+}
+
+bool FrameHasPriority(const Http2FrameHeader& header) {
+  switch (header.type) {
+    case Http2FrameType::HEADERS:
+      return header.HasPriority();
+    case Http2FrameType::PRIORITY:
+      return true;
+    default:
+      return false;
+  }
+}
+
+bool FrameCanHavePayload(const Http2FrameHeader& header) {
+  switch (header.type) {
+    case Http2FrameType::DATA:
+    case Http2FrameType::HEADERS:
+    case Http2FrameType::PUSH_PROMISE:
+    case Http2FrameType::CONTINUATION:
+    case Http2FrameType::PING:
+    case Http2FrameType::GOAWAY:
+    case Http2FrameType::ALTSVC:
+      return true;
+    default:
+      return false;
+  }
+}
+
+bool FrameCanHaveHpackPayload(const Http2FrameHeader& header) {
+  switch (header.type) {
+    case Http2FrameType::HEADERS:
+    case Http2FrameType::PUSH_PROMISE:
+    case Http2FrameType::CONTINUATION:
+      return true;
+    default:
+      return false;
+  }
+}
+
+}  // namespace test
+}  // namespace http2