Create a new RenderFrameHost per child frame when --site-per-process is enabled.

content/browser/renderer_host/render_frame_message_filter.h

Index: content/browser/renderer_host/render_frame_message_filter.h
diff --git a/content/browser/renderer_host/render_frame_message_filter.h b/content/browser/renderer_host/render_frame_message_filter.h
new file mode 100644
index 0000000000000000000000000000000000000000..2ef560a5cc1bfe4a4f72bbb29a53cf6becf91ee4
--- /dev/null
+++ b/content/browser/renderer_host/render_frame_message_filter.h
@@ -0,0 +1,36 @@
+// Copyright (c) 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.
+
+#ifndef CONTENT_BROWSER_RENDERER_HOST_RENDER_FRAME_MESSAGE_FILTER_H_
+#define CONTENT_BROWSER_RENDERER_HOST_RENDER_FRAME_MESSAGE_FILTER_H_
+
+#include "content/public/browser/browser_message_filter.h"
+
+namespace content {
+class RenderWidgetHelper;
+
+class RenderFrameMessageFilter : public BrowserMessageFilter {

[Charlie Reis, 2013/09/11 22:25:04]

Are things going to migrate here from some RenderView-related filter?

[awong, 2013/09/21 01:19:56]

Hopefully not too many things...

We should only need this message filter for things that need to avoid the UI
thread. Currently, that's just routing_id allocation for a new child frame.

+ public:
+  RenderFrameMessageFilter(int render_process_id,
+                           RenderWidgetHelper* render_widget_helper);
+
+  virtual bool OnMessageReceived(const IPC::Message& message,
+                                 bool* message_was_ok) OVERRIDE;
+
+ private:
+  void OnCreateChildFrame(int parent_render_frame_id,
+                          int64 parent_frame_id,
+                          int64 frame_id,
+                          const std::string& frame_name,
+                          int* new_render_frame_id);
+
+  const int render_process_id_;
+
+  // Needed for issuing routing ids and surface ids.
+  scoped_refptr<RenderWidgetHelper> render_widget_helper_;
+};
+
+}  // namespace content
+
+#endif  // CONTENT_BROWSER_RENDERER_HOST_RENDER_FRAME_MESSAGE_FILTER_H_