[Cast Channel] Fix "leaky" CastChannelOpenFunction.

extensions/browser/api/cast_channel/cast_channel_api.cc

 // 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.
 
 #include "extensions/browser/api/cast_channel/cast_channel_api.h"
 
 #include <stddef.h>
 #include <stdint.h>
 
 #include <limits>
@@ skipping 328 matching lines @@
     delegate.reset(keep_alive);
   }
 
   socket->Connect(std::move(delegate),
                   base::Bind(&CastChannelOpenFunction::OnOpen, this));
 }
 
 void CastChannelOpenFunction::OnOpen(cast_channel::ChannelError result) {
   DCHECK_CURRENTLY_ON(BrowserThread::IO);
   VLOG(1) << "Connect finished, OnOpen invoked.";
-  CastSocket* socket = GetSocket(new_channel_id_);
-  if (!socket) {
+  // TODO: If we failed to open the CastSocket, we may want to clean up here,
+  // rather than relying on the extension to call close(). This can be done by
+  // calling RemoveSocket() and api_->GetLogger()->ClearLastErrors(channel_id).
+  if (result != cast_channel::CHANNEL_ERROR_UNKNOWN) {
+    CastSocket* socket = GetSocket(new_channel_id_);
+    CHECK(socket);
+    SetResultFromSocket(*socket);
+  } else {
+    // The socket is being destroyed.
     SetResultFromError(new_channel_id_, result);
-  } else {
-    SetResultFromSocket(*socket);
   }
+
   AsyncWorkCompleted();
 }
 
 CastChannelSendFunction::CastChannelSendFunction() { }
 
 CastChannelSendFunction::~CastChannelSendFunction() { }
 
 bool CastChannelSendFunction::Prepare() {
   params_ = Send::Params::Create(*args_);
   EXTENSION_FUNCTION_VALIDATE(params_.get());
@@ skipping 147 matching lines @@
   BrowserThread::PostTask(
       BrowserThread::UI, FROM_HERE,
       base::Bind(ui_dispatch_cb_, socket_->owner_extension_id(),
                  base::Passed(std::move(event))));
 }
 
 void CastChannelOpenFunction::CastMessageHandler::Start() {
 }
 
 }  // namespace extensions