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

net/websockets/websocket_channel.cc

 // Copyright 2013 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/websockets/websocket_channel.h"
 
 #include <limits.h>  // for INT_MAX
 
 #include <algorithm>
 #include <deque>
@@ skipping 447 matching lines @@
       (state_ == CONNECTED || state_ == SEND_CLOSED || state_ == CLOSE_WAIT);
   current_receive_quota_ += base::checked_cast<int>(quota);
   if (start_read)
     AllowUnused(ReadFrames());
   // |this| may have been deleted.
 }
 
 void WebSocketChannel::StartClosingHandshake(uint16 code,
                                              const std::string& reason) {
   if (InClosingState()) {
+    // When the associated renderer process is killed while the channel is in
+    // CLOSING state we reach here.
     DVLOG(1) << "StartClosingHandshake called in state " << state_
              << ". This may be a bug, or a harmless race.";
     return;
   }
   if (state_ == CONNECTING) {
     // Abort the in-progress handshake and drop the connection immediately.
     stream_request_.reset();
     SetState(CLOSED);
     AllowUnused(DoDropChannel(false, kWebSocketErrorAbnormalClosure, ""));
     return;
@@ skipping 627 matching lines @@
 }
 
 void WebSocketChannel::CloseTimeout() {
   stream_->Close();
   SetState(CLOSED);
   AllowUnused(DoDropChannel(false, kWebSocketErrorAbnormalClosure, ""));
   // |this| has been deleted.
 }
 
 }  // namespace net