Delegate WebSocket message handlers to the loading task runner

content/child/websocket_message_filter.cc

Index: content/child/websocket_message_filter.cc
diff --git a/content/child/websocket_message_filter.cc b/content/child/websocket_message_filter.cc
new file mode 100644
index 0000000000000000000000000000000000000000..9f8cc4afcfc83540d968fd9b9b0d50bf1b4906a7
--- /dev/null
+++ b/content/child/websocket_message_filter.cc
@@ -0,0 +1,32 @@
+// Copyright 2016 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 "content/child/websocket_message_filter.h"
+
+#include "base/bind.h"
+#include "base/single_thread_task_runner.h"
+#include "content/child/websocket_dispatcher.h"
+#include "ipc/ipc_message.h"
+
+namespace content {
+
+WebSocketMessageFilter::WebSocketMessageFilter(
+    WebSocketDispatcher* websocket_dispatcher)
+  : websocket_dispatcher_(websocket_dispatcher) {}
+
+WebSocketMessageFilter::~WebSocketMessageFilter() {}
+
+bool WebSocketMessageFilter::OnMessageReceived(const IPC::Message& message) {
+  if (!WebSocketDispatcher::CanHandleMessage(message))
+    return false;
+  // |websocket_dispatcher_| is owned by a RenderThreadImpl and lives when the
+  // renderer process lives.
+  loading_task_runner_->PostTask(FROM_HERE, base::Bind(
+      base::IgnoreResult(&WebSocketDispatcher::OnMessageReceived),
+      base::Unretained(websocket_dispatcher_),

[kinuko, 2016/05/26 08:15:35]

I might be just too nervouse, but I'm not fully happy with this as this could
get broken if any changes are made in renderer thread lifecycle and the
description 'when the renderer process lives' feels a bit unclear (while it
seems it's true that RenderThreadImpl isn't freed in production code), and where
websocket_dispatcher_ lives is actually on ChildThreadImpl...

Could we still make this a bit nicer?  E.g. having a glue method on this to post
task to using weak-ptr of this class, have Shutdown() method which invalidates
all weak-ptrs and let ChildThreadImpl::Shutdown() call it?

[hajimehoshi, 2016/05/26 09:49:02]

Done.

+      message));
+  return true;
+}
+
+}  // namespace content