Create a new RenderFrameHost per child frame when --site-per-process is enabled.

content/browser/renderer_host/frame_tree_node.cc

Index: content/browser/renderer_host/frame_tree_node.cc
diff --git a/content/browser/renderer_host/frame_tree_node.cc b/content/browser/renderer_host/frame_tree_node.cc
new file mode 100644
index 0000000000000000000000000000000000000000..32ef9866b228479e88173f532a32aa9ac1e6de83
--- /dev/null
+++ b/content/browser/renderer_host/frame_tree_node.cc
@@ -0,0 +1,55 @@
+// 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/renderer_host/frame_tree_node.h"
+
+#include <queue>
+
+#include "base/stl_util.h"
+#include "content/browser/renderer_host/render_frame_host_impl.h"
+
+namespace content {
+
+const int64 FrameTreeNode::kInvalidFrameId;
+
+FrameTreeNode::FrameTreeNode(int64 frame_id, const std::string& name,
+                             scoped_ptr<RenderFrameHostImpl> render_frame_host)
+  : frame_id_(frame_id),
+    frame_name_(name),
+    owns_render_frame_host_(true),
+    render_frame_host_(render_frame_host.release()) {
+}
+
+FrameTreeNode::~FrameTreeNode() {
+  if (owns_render_frame_host_)
+    delete render_frame_host_;
+}
+
+void FrameTreeNode::AddChild(scoped_ptr<FrameTreeNode> child) {
+  children_.push_back(child.release());
+}
+
+void FrameTreeNode::RemoveChild(int64 child_id) {
+  std::vector<FrameTreeNode*>::iterator iter;
+
+  for (iter = children_.begin(); iter != children_.end(); ++iter) {
+    if ((*iter)->frame_id() == child_id)
+      break;
+  }
+
+  if (iter != children_.end())
+    children_.erase(iter);
+}
+
+void FrameTreeNode::ResetForMainFrame(
+    RenderFrameHostImpl* new_render_frame_host) {
+  owns_render_frame_host_ = false;
+  frame_id_ = kInvalidFrameId;
+  current_url_ = GURL();
+  children_.clear();
+
+  render_frame_host_ = new_render_frame_host;
+}
+
+}  // namespace content