Adds the ability for the renderer to create the mojo channel

content/renderer/mojo_message_filter.cc

Index: content/renderer/mojo_message_filter.cc
diff --git a/content/renderer/mojo_message_filter.cc b/content/renderer/mojo_message_filter.cc
new file mode 100644
index 0000000000000000000000000000000000000000..a045a680e330dbc83bf784b72d0adce8be7247d8
--- /dev/null
+++ b/content/renderer/mojo_message_filter.cc
@@ -0,0 +1,50 @@
+// 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 "content/renderer/mojo_message_filter.h"
+
+#include "base/message_loop/message_loop.h"
+#include "content/child/child_process.h"
+#include "content/common/mojo/mojo_channel_init.h"
+#include "content/common/mojo/mojo_messages.h"
+#include "content/public/renderer/render_thread.h"
+
+namespace content {
+
+MojoMessageFilter::MojoMessageFilter(RenderThread* render_thread)
+    : render_thread_(render_thread) {
+  render_thread_->AddObserver(this);
+}
+
+bool MojoMessageFilter::OnControlMessageReceived(const IPC::Message& message) {
+  bool handled = true;
+  IPC_BEGIN_MESSAGE_MAP(MojoMessageFilter, message)
+    IPC_MESSAGE_HANDLER(MojoMsg_ChannelCreated, OnChannelCreated)
+    IPC_MESSAGE_UNHANDLED(handled = false)
+  IPC_END_MESSAGE_MAP()
+  return handled;
+}
+
+void MojoMessageFilter::OnRenderProcessShutdown() {
+  delete this;
+}
+
+MojoMessageFilter::~MojoMessageFilter() {
+  render_thread_->RemoveObserver(this);
+}
+
+void MojoMessageFilter::OnChannelCreated(
+    const IPC::PlatformFileForTransit& file) {
+#if defined(OS_POSIX)
+  base::PlatformFile handle = file.fd;
+#elif defined(OS_WIN)
+  base::PlatformFile handle = file;
+#endif
+  DCHECK(!channel_init_.get());
+  channel_init_.reset(new MojoChannelInit);
+  channel_init_->Init(handle,
+      ChildProcess::current()->current()->io_message_loop_proxy());

[darin (slow to review), 2014/03/14 22:03:36]

nit: did you mean to call current()->current()? isn't the second call
unnecessary?

[sky, 2014/03/14 22:45:12]

My mistake. Done.

+}
+
+}  // namespace content