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

content/common/frame_messages.h

Index: content/common/frame_messages.h
diff --git a/content/common/frame_messages.h b/content/common/frame_messages.h
new file mode 100644
index 0000000000000000000000000000000000000000..a40bbcb1a3b6d5583cc43b7833118d158cc8766c
--- /dev/null
+++ b/content/common/frame_messages.h
@@ -0,0 +1,34 @@
+// 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.
+
+// IPC messages for interacting with frames.
+// Multiply-included message file, hence no include guard.
+
+#include "content/common/content_export.h"
+#include "ipc/ipc_message_macros.h"
+
+#undef IPC_MESSAGE_EXPORT
+#define IPC_MESSAGE_EXPORT CONTENT_EXPORT
+
+#define IPC_MESSAGE_START FrameMsgStart
+
+// Similar to ViewHostMsg_CreateWindow, except used for sub-frames like
+// and <iframe>.

[nasko, 2013/09/11 22:26:24]

nit: "an" instead of "and"?

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

Done.

+//
+// TODO(ajwong): Remove ViewHostMsg_FrameAttached once a RenderFrame is
+// guaranteed to be created per WebCore::Frame, and WebCore::identifier() has
+// been replaced by.

[nasko, 2013/09/11 22:26:24]

Replaced by what?

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

Done.

+IPC_SYNC_MESSAGE_CONTROL4_1(FrameHostMsg_CreateChildFrame,
+                            int /* parent_render_frame_id */,

[nasko, 2013/09/11 22:26:24]

Would it help to be explicit and use int32? I know they are equivalent, but it
doesn't hurt IMHO.

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

sure.

+                            int64 /* parent_frame_id */,
+                            int64 /* frame_id */,
+                            std::string /* frame_name */,
+                            int /* new_render_frame_id */)
+
+// TODO(ajwong): Remove ViewHostMsg_FrameDetached once a RenderFrame is
+// guaranteed to be created per WebCore::Frame.
+IPC_MESSAGE_ROUTED2(FrameHostMsg_Detach,
+                    int64 /* parent_frame_id */,
+                    int64 /* frame_id */)
+