gfe-relnote: Move Http2PriorityWriteScheduler from gfe/gfe2/spdy/ to third_party/spdy/core/ to allow QUIC to use it. No functional change expected, not flag protected.

Also copy gtl::intrusive_list as SpdyIntrusiveList.

PiperOrigin-RevId: 259535206
Change-Id: Ie600cc4a403ac90a6302824f98bc5e7fd86fca25
diff --git a/spdy/platform/api/spdy_map_util.h b/spdy/platform/api/spdy_map_util.h
new file mode 100644
index 0000000..e9b5f85
--- /dev/null
+++ b/spdy/platform/api/spdy_map_util.h
@@ -0,0 +1,19 @@
+// Copyright (c) 2019 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.
+
+#ifndef QUICHE_SPDY_PLATFORM_API_SPDY_MAP_UTIL_H_
+#define QUICHE_SPDY_PLATFORM_API_SPDY_MAP_UTIL_H_
+
+#include "net/spdy/platform/impl/spdy_map_util_impl.h"
+
+namespace spdy {
+
+template <class Collection, class Key>
+bool SpdyContainsKey(const Collection& collection, const Key& key) {
+  return SpdyContainsKeyImpl(collection, key);
+}
+
+}  // namespace spdy
+
+#endif  // QUICHE_SPDY_PLATFORM_API_SPDY_MAP_UTIL_H_