Remove existing FrameNavigationEntry when new named frame is added.

content/browser/frame_host/frame_tree.cc

Index: content/browser/frame_host/frame_tree.cc
diff --git a/content/browser/frame_host/frame_tree.cc b/content/browser/frame_host/frame_tree.cc
index 4dcf54140956a2165fbd03bba4f3a24a52f38584..9e054eb70ab0376f86d59d63f10b725e54488803 100644
--- a/content/browser/frame_host/frame_tree.cc
+++ b/content/browser/frame_host/frame_tree.cc
@@ -15,6 +15,7 @@
 #include "base/lazy_instance.h"
 #include "base/memory/ptr_util.h"
 #include "content/browser/frame_host/frame_tree_node.h"
+#include "content/browser/frame_host/navigation_entry_impl.h"

[Charlie Reis, 2016/07/27 22:48:27]

I suppose we should include NavigationController as well.  I'm not thrilled
about adding this dependency here, but I suppose there's no good reason to add a
hop through NavigatorImpl for this.

[nasko, 2016/07/29 15:52:19]

Acknowledged.

 #include "content/browser/frame_host/navigator.h"
 #include "content/browser/frame_host/render_frame_host_factory.h"
 #include "content/browser/frame_host/render_frame_host_impl.h"
@@ -184,6 +185,14 @@ bool FrameTree::AddFrame(FrameTreeNode* parent,
   if (parent->current_frame_host()->GetProcess()->GetID() != process_id)
     return false;
 
+  // If the last committed NavigationEntry has FrameNavigationEntry with the
+  // same |frame_unique_name|, it has to be removed to avoid conflicts with
+  // future updates.

[Charlie Reis, 2016/07/27 22:48:27]

Let's clarify a bit how this is an expected case:

The last committed NavigationEntry may have a FrameNavigationEntry with the same
|frame_unique_name|, since we don't remove FrameNavigationEntries if their
frames are deleted.  If there is a stale one, remove it to avoid conflicts on
future updates.

[nasko, 2016/07/29 15:52:19]

Done.

+  NavigationEntryImpl* last_committed_entry = static_cast<NavigationEntryImpl*>(
+      root_->navigator()->GetController()->GetLastCommittedEntry());

[Charlie Reis, 2016/07/27 22:48:27]

This should be parent->navigator() to be consistent with line 199 below.

[nasko, 2016/07/29 15:52:19]

Done.

+  if (last_committed_entry)
+    last_committed_entry->ClearNamedFrameEntries(frame_unique_name);
+
   // AddChild is what creates the RenderFrameHost.
   FrameTreeNode* added_node = parent->AddChild(
       base::WrapUnique(new FrameTreeNode(