Introduce content::ChildMessageFilter.

content/child/child_message_filter.cc

Index: content/child/child_message_filter.cc
diff --git a/content/child/child_message_filter.cc b/content/child/child_message_filter.cc
new file mode 100644
index 0000000000000000000000000000000000000000..7c621798367dfac15162db808905c2846afe8208
--- /dev/null
+++ b/content/child/child_message_filter.cc
@@ -0,0 +1,41 @@
+// 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 "content/child/child_message_filter.h"
+
+#include "content/child/child_thread.h"
+#include "content/child/thread_safe_sender.h"
+
+namespace content {
+
+ChildMessageFilter::ChildMessageFilter()
+    : thread_safe_sender_(ChildThread::current()->thread_safe_sender()) {}
+
+ChildMessageFilter::~ChildMessageFilter() {}
+
+bool ChildMessageFilter::OnMessageReceived(const IPC::Message& message) {
+  scoped_refptr<base::TaskRunner> runner =
+      OverrideTaskRunnerForMessage(message);
+  if (runner) {
+    runner->PostTask(
+        FROM_HERE,
+        base::Bind(base::IgnoreResult(&ChildMessageFilter::HandleMessage),
+                   this,
+                   message));
+    return true;
+  }
+
+  return HandleMessage(message);
+}
+
+bool ChildMessageFilter::Send(IPC::Message* message) {
+  return thread_safe_sender_->Send(message);
+}
+
+base::TaskRunner* ChildMessageFilter::OverrideTaskRunnerForMessage(
+    const IPC::Message& message) {
+  return NULL;
+}
+
+}  // namespace content