Point out in the comments the equivalence of two observer functions.

content/public/browser/render_process_host_observer.h

Index: content/public/browser/render_process_host_observer.h
diff --git a/content/public/browser/render_process_host_observer.h b/content/public/browser/render_process_host_observer.h
index 2bd9fc1e76759e59ea37a168b48ab5fe2672c210..293a5db9d29f8619731af2fb24627ecc9f698203 100644
--- a/content/public/browser/render_process_host_observer.h
+++ b/content/public/browser/render_process_host_observer.h
@@ -20,6 +20,8 @@ class CONTENT_EXPORT RenderProcessHostObserver {
   // This method is invoked when a render process exited (either normally or
   // with a crash). To determine if the process closed normally or crashed,
   // examine the |status| parameter.
+  //
+  // Note that this is equivalent to WebContentsObserver::RenderProcessGone().
   virtual void RenderProcessExited(RenderProcessHost* host,
                                    base::ProcessHandle handle,
                                    base::TerminationStatus status,