Revert of OOPIF: Specify previous sibling frames when creating new RenderFrames.

content/browser/frame_host/render_frame_host_impl.h

Index: content/browser/frame_host/render_frame_host_impl.h
diff --git a/content/browser/frame_host/render_frame_host_impl.h b/content/browser/frame_host/render_frame_host_impl.h
index e0a03c78955fc62c02b3689926f421dcc073d046..732455259da3a6c6ca1da0a4a34a09944e953e3d 100644
--- a/content/browser/frame_host/render_frame_host_impl.h
+++ b/content/browser/frame_host/render_frame_host_impl.h
@@ -179,9 +179,7 @@
 
   // Creates a RenderFrame in the renderer process.  Only called for
   // cross-process subframe navigations in --site-per-process.
-  bool CreateRenderFrame(int parent_routing_id,
-                         int previous_sibling_routing_id,
-                         int proxy_routing_id);
+  bool CreateRenderFrame(int parent_routing_id, int proxy_routing_id);
 
   // Returns whether the RenderFrame in the renderer process has been created
   // and still has a connection.  This is valid for all frames.