Update the documentation for LoadCommittedDetails::previous_url.

content/public/browser/navigation_details.h

Index: content/public/browser/navigation_details.h
diff --git a/content/public/browser/navigation_details.h b/content/public/browser/navigation_details.h
index 19c852d2b141f46e4e355da77630de7068fe6a2e..b34410578f4da708046f77b61745f98e7310fed6 100644
--- a/content/public/browser/navigation_details.h
+++ b/content/public/browser/navigation_details.h
@@ -35,7 +35,8 @@ struct CONTENT_EXPORT LoadCommittedDetails {
   // if there are no previous entries.
   int previous_entry_index;
 
-  // The previous URL that the user was on. This may be empty if none.
+  // The previous main frame URL that the user was on. This may be empty if
+  // there was no last committed entry.

[Avi (use Gerrit), 2015/11/09 22:42:24]

How does this interact with your change to make sure there always is a
last-committed entry? :)

[Charlie Reis, 2015/11/09 22:55:28]

Yep, it won't be possible after https://codereview.chromium.org/1309323004/.  I
hadn't updated the previous_url case yet in that CL, but I just left myself a
note to do it.  :)

   GURL previous_url;
 
   // True if the committed entry has replaced the exisiting one.