Add frame_tree_node_id to navigation parameters.

content/browser/frame_host/navigation_entry_impl.h

Index: content/browser/frame_host/navigation_entry_impl.h
diff --git a/content/browser/frame_host/navigation_entry_impl.h b/content/browser/frame_host/navigation_entry_impl.h
index 1149ae6ec5fb11162e6965b16dcfad9dca299a11..586d654d2af7cd3f5aa63f1e788dc81f79e7e6b1 100644
--- a/content/browser/frame_host/navigation_entry_impl.h
+++ b/content/browser/frame_host/navigation_entry_impl.h
@@ -216,6 +216,15 @@ class CONTENT_EXPORT NavigationEntryImpl
     should_clear_history_list_ = should_clear_history_list;
   }
 
+  // Indicates which FrameTreeNode to navigate.  Currently only used if the
+  // --site-per-process flag is passed.
+  int64 frame_tree_node_id() const {
+    return frame_tree_node_id_;
+  }
+  void set_frame_tree_node_id(int64 frame_tree_node_id) {
+    frame_tree_node_id_ = frame_tree_node_id;
+  }
+
  private:
   // WARNING WARNING WARNING WARNING WARNING WARNING WARNING WARNING WARNING
   // Session/Tab restore save portions of this class so that it can be recreated
@@ -323,6 +332,12 @@ class CONTENT_EXPORT NavigationEntryImpl
   // persisted, because it is currently only used in tests.
   std::string frame_to_navigate_;
 
+  // If not -1, this indicates which FrameTreeNode to navigate.  This field is
+  // not persisted because it is experimental and only used when the

[nasko, 2013/11/20 18:01:30]

Before we get to FrameNavigationEntry, what would this value be subframes in a
document? AUTO_SUBFRAME navigations just pile onto the same NavigationEntry, so
do we just drop those ids for the time being?

[Charlie Reis, 2013/11/20 21:43:06]

Good question.  Without the flag, subframe navigations don't have pending
NavigationEntries, so it's not an issue (always -1).

Once we start creating pending entries for subframes behind the flag, the
pending entry exists but gets thrown away in RendererDidNavigateSubframe, so the
last committed NavigationEntry isn't affected and keeps an ID of -1.

That said, I did forget to add it to ResetForCommit, since we don't need the
value after commit.  I've updated that.

+  // --site-per-process flag is passed.
+  // TODO(creis): Move this to FrameNavigationEntry.
+  int64 frame_tree_node_id_;
+
   // Used to store extra data to support browser features. This member is not
   // persisted, unless specific data is taken out/put back in at save/restore
   // time (see TabNavigation for an example of this).