Remove existing FrameNavigationEntry when new named frame is added.

content/browser/frame_host/navigation_entry_impl.cc

 // 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.
 
 #include "content/browser/frame_host/navigation_entry_impl.h"
 
 #include <stddef.h>
 
 #include <queue>
 #include <utility>
@@ skipping 770 matching lines @@
   NavigationEntryImpl::TreeNode* tree_node = FindFrameEntry(frame_tree_node);
   return tree_node ? tree_node->frame_entry.get() : nullptr;
 }
 
 void NavigationEntryImpl::ClearChildren(FrameTreeNode* frame_tree_node) {
   NavigationEntryImpl::TreeNode* tree_node = FindFrameEntry(frame_tree_node);
   if (tree_node)
     tree_node->children.clear();
 }
 
+void NavigationEntryImpl::ClearMatchingFrameEntries(
+    FrameTreeNode* frame_tree_node) {
+  DCHECK(!frame_tree_node->IsMainFrame());
+
+  bool match_found = false;
+  NavigationEntryImpl::TreeNode* node = nullptr;
+  NavigationEntryImpl::TreeNode* parent_node = nullptr;
+  std::map<NavigationEntryImpl::TreeNode*, NavigationEntryImpl::TreeNode*>
+      parenting_map;
+  std::queue<NavigationEntryImpl::TreeNode*> work_queue;
+  work_queue.push(root_node());
+  parenting_map.insert(std::make_pair(root_node(), nullptr));
+
+  while (!work_queue.empty()) {
+    node = work_queue.front();
+    parent_node = parenting_map.find(node)->second;
+    work_queue.pop();
+
+    if (node->MatchesFrame(frame_tree_node, node == root_node())) {
+      match_found = true;
+      break;

[Charlie Reis, 2016/07/28 22:57:01]

It's a little unfortunate that we stop after the first match.  Hopefully we'll
never see a case with more than one stale entry, but if there were one it'd be
hard to track down.

Would it be possible to call a helper to do the ancestor walk here, and then
continue as you were before?

[nasko, 2016/07/29 15:52:22]

Done.

+    }
+
+    // Enqueue any children and keep looking.
+    for (auto* child : node->children) {
+      work_queue.push(child);
+      parenting_map.insert(std::make_pair(child, node));
+    }
+  }
+
+  if (!match_found)
+    return;
+
+  // Walk the ancestor chain for both the FrameTreeNode and the
+  // FrameNavigationEntry. If a mismatch in unique name is detected, the
+  // matched FrameNavigationEntry needs to be removed.
+  // The FTN and FNE are a match, guaranteed by the while loop above.
+  // Start with the parent nodes.
+  FrameTreeNode* ftn = frame_tree_node->parent();
+  TreeNode* current_node = parent_node;
+  while (ftn && current_node) {
+    if (!current_node->MatchesFrame(ftn, current_node == root_node())) {
+      auto it = std::find(parent_node->children.begin(),
+                          parent_node->children.end(), node);
+      DCHECK(it != parent_node->children.end());
+      parent_node->children.erase(it);
+      break;
+    }
+    ftn = ftn->parent();
+    auto it = parenting_map.find(current_node);
+    if (it != parenting_map.end())
+      current_node = it->second;

[Charlie Reis, 2016/07/28 22:57:01]

Need to handle the else branch, right?  (If the FTN has a parent and the FNE
does not, then the trees don't match.)

[nasko, 2016/07/29 15:52:22]

Done.

+  }
+}
+
 void NavigationEntryImpl::SetScreenshotPNGData(
     scoped_refptr<base::RefCountedBytes> png_data) {
   screenshot_ = png_data;
   if (screenshot_.get())
     UMA_HISTOGRAM_MEMORY_KB("Overscroll.ScreenshotSize", screenshot_->size());
 }
 
 GURL NavigationEntryImpl::GetHistoryURLForDataURL() const {
   return GetBaseURLForDataURL().is_empty() ? GURL() : GetVirtualURL();
 }
@@ skipping 10 matching lines @@
       return node;
 
     // Enqueue any children and keep looking.
     for (auto* child : node->children)
       work_queue.push(child);
   }
   return nullptr;
 }
 
 }  // namespace content