OOPIF: Remove the FrameTreeNode when a RemoteFrame is detached.

content/browser/frame_host/frame_tree_node.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/frame_tree_node.h"
 
 #include <queue>
 
 #include "base/command_line.h"
 #include "base/stl_util.h"
@@ skipping 151 matching lines @@
   return current_frame_host->loading_progress();
 }
 
 bool FrameTreeNode::CommitPendingSandboxFlags() {
   bool did_change_flags =
       effective_sandbox_flags_ != replication_state_.sandbox_flags;
   effective_sandbox_flags_ = replication_state_.sandbox_flags;
   return did_change_flags;
 }
 
+bool FrameTreeNode::HasAncestorFrom(SiteInstance* site_instance) const {
+  FrameTreeNode* parent_node = parent();
+  while (parent_node) {
+    if (parent_node->current_frame_host()->GetSiteInstance() == site_instance)
+      return true;
+    parent_node = parent_node->parent();
+  }
+  return false;
+}
+
 }  // namespace content