Update from https://crrev.com/312398

net/data/websocket/echo-request-headers_wsh.py

Index: net/data/websocket/echo-request-headers_wsh.py
diff --git a/net/data/websocket/echo-request-headers_wsh.py b/net/data/websocket/echo-request-headers_wsh.py
new file mode 100644
index 0000000000000000000000000000000000000000..89aa28ea20ab084dc2d9d719a51070865e71fa21
--- /dev/null
+++ b/net/data/websocket/echo-request-headers_wsh.py
@@ -0,0 +1,20 @@
+# 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.
+#
+# This handler serializes the received headers into a JSON string and sends it
+# back to the client. In |headers_in|, the keys are converted to lower-case,
+# while the original case is retained for the values.
+
+
+import json
+
+
+def web_socket_do_extra_handshake(request):
+    pass
+
+
+def web_socket_transfer_data(request):
+    request.ws_stream.send_message(json.dumps(dict(request.headers_in.items())))
+    # Wait for closing handshake
+    request.ws_stream.receive_message()