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

net/data/websocket/README

 This directory contains resources used by WebSocket server for testing.
 Multiple tests may share one resource, or URI handler.
 
 - connect_check.html : A page provides simple WebSocket connectivity check.
      This page changes page title to "PASS" to notify content::TitleWatcher.
      Used by ProxyBrowserTest.BasicAuthWSConnect,
      SSLUITest.TestWSSInvalidCertAndGoForward, SSLUITest.TestWSSClientCert,
      and SSLUITestIgnoreCertErrors.TestWSS.
 
 - split_packet_check.html : A page for testing split packet handling. Here,
      packets mean TCP segments for WebSocket, or SSL records for secure
      WebSocket. This page changes the title to "PASS" to notify
      content::TitleWatcher.
      Used by WebSocketBrowserTest.WebSocketSplitSegments and
      WebSocketBrowserTest.SecureWebSocketSplitRecords.
 
 - websocket_shared_worker.html :  A page provides simple WebSocket test in
      shared worker. This page changes page title to "PASS" to notify
      content::TitleWatcher.
      Used by WorkerTest.WebSocketSharedWorker.
 
+- counted-connection.html : A page that creates a WebSocket connection
+     to count-connection_wsh.
+     This file does NOT close the established connection.
+     Used by SendCloseFrameWhenTabIsClosed.
+
+- count-connection.html : A page that creates a WebSocket connection
+     to count-connection_wsh and checks the number of open and closed
+     websocket connections to the handler.
+     Used by SendCloseFrameWhenTabIsClosed.
+
 - websocket_worker_simple.js : A JavaScript runs on Workers created from the
      websocket_shared_worker.html.
      Used by WorkerTest.WebSocketSharedWorker.
 
 - echo-with-no-extension_wsh.py : A WebSocket URL handler for echo testing.
      This handler disables all WebSocket extension so that we can perform
      frame data dependent tests.
      Used by kinds of PPAPI tests for WebSocket, ExtensionApiTest.WebSocket,
      and WorkerTest.WebSocketSharedWorker.
 
 - close_wsh.py : A WebSocket URL handler for testing outgoing close code and
      reason.
      Used by kinds of PPAPI tests for WebSocket.
 
 - close-code-and-reason_wsh.py : A WebSocket URL handler for testing server
      initiated closing handshake. A client can ask server to close the
      connection with arbitrary code and reason.
      Used by kinds of PPAPI tests for WebSocket.
 
 - close-with-split-packet_wsh.py : A WebSocket URL handler for testing split
      packet handling. Here, packets mean TCP segments for WebSocket, or SSL
      records for secure WebSocket.
      Used by WebSocketBrowserTest.WebSocketSplitSegments and
      WebSocketBrowserTest.SecureWebSocketSplitRecords.
 
+- count-connection_wsh.py : counts the number of open and closed websocket
+     connections to this handler.
+     It sends the numbers after each connection establishment.
+     Used by SendCloseFrameWhenTabIsClosed.
+
 - protocol-test_wsh.py : A WebSocket URL handler for testing outgoing opening
      handshake protocol.
      Used by kinds of PPAPI tests for WebSocket.