[WebSocket] Send a close frame when the renderer process is gone.

net/data/websocket/count-connection_wsh.py

+# Copyright 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.
+
+numOpenConnections = 0
+numClosedConnections = 0
+
+
+def web_socket_do_extra_handshake(request):
+  global numOpenConnections
+  numOpenConnections += 1
+
+
+def web_socket_transfer_data(request):
+  request.ws_stream.send_message('open: %d, closed: %d' %
+      (numOpenConnections, numClosedConnections), binary=False)
+  # Just waiting...
+  request.ws_stream.receive_message()
+
+
+def web_socket_passive_closing_handshake(request):
+  global numOpenConnections
+  global numClosedConnections
+  numOpenConnections -= 1
+  numClosedConnections += 1
+  return (1000, '')