Add frame_tree_node_id to navigation parameters.

content/browser/frame_host/navigation_entry_impl.h

 // Copyright 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.
 
 #ifndef CONTENT_BROWSER_FRAME_HOST_NAVIGATION_ENTRY_IMPL_H_
 #define CONTENT_BROWSER_FRAME_HOST_NAVIGATION_ENTRY_IMPL_H_
 
 #include "base/basictypes.h"
 #include "base/memory/ref_counted.h"
 #include "content/browser/site_instance_impl.h"
@@ skipping 198 matching lines @@
 
   // Whether this (pending) navigation should clear the session history. Resets
   // to false after commit.
   bool should_clear_history_list() const {
     return should_clear_history_list_;
   }
   void set_should_clear_history_list(bool should_clear_history_list) {
     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
   // later. If you add a new field that needs to be persisted you'll have to
   // update SessionService/TabRestoreService and Android WebView
   // state_serializer.cc appropriately.
   // WARNING WARNING WARNING WARNING WARNING WARNING WARNING WARNING WARNING
 
   // See the accessors above for descriptions.
   int unique_id_;
@@ skipping 87 matching lines @@
   bool should_clear_history_list_;
 
   // Set when this entry should be able to access local file:// resources. This
   // value is not needed after the entry commits and is not persisted.
   bool can_load_local_resources_;
 
   // If not empty, the name of the frame to navigate. This field is not
   // 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).
   std::map<std::string, string16> extra_data_;
 
   // Copy and assignment is explicitly allowed for this class.
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_FRAME_HOST_NAVIGATION_ENTRY_IMPL_H_