Make RenderFrameHostManager swap RenderFrameHosts, not RenderViewHosts.

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/stl_util.h"
 #include "content/browser/frame_host/navigator.h"
 #include "content/browser/frame_host/render_frame_host_impl.h"
+#include "content/browser/renderer_host/render_view_host_impl.h"
 
 namespace content {
 
 const int64 FrameTreeNode::kInvalidFrameId = -1;
 int64 FrameTreeNode::next_frame_tree_node_id_ = 1;
 
 FrameTreeNode::FrameTreeNode(Navigator* navigator,
                              RenderFrameHostDelegate* render_frame_delegate,
                              RenderViewHostDelegate* render_view_delegate,
                              RenderWidgetHostDelegate* render_widget_delegate,
                              RenderFrameHostManager::Delegate* manager_delegate,
                              int64 frame_id,
                              const std::string& name)
   : navigator_(navigator),
     render_manager_(render_frame_delegate,
                     render_view_delegate,
                     render_widget_delegate,
                     manager_delegate),
     frame_tree_node_id_(next_frame_tree_node_id_++),
     frame_id_(frame_id),
-    frame_name_(name),
-    owns_render_frame_host_(true),
-    render_frame_host_(NULL) {
+    frame_name_(name) {
 }
 
 FrameTreeNode::~FrameTreeNode() {
-  if (owns_render_frame_host_)
-    delete render_frame_host_;
 }
 
-void FrameTreeNode::AddChild(scoped_ptr<FrameTreeNode> child) {
+void FrameTreeNode::AddChild(scoped_ptr<FrameTreeNode> child,
+                             int render_frame_host_id) {

[nasko, 2013/12/12 02:22:12]

nit: This is a bit unclear. This is the routing id of the RFH, right? Let's call
it render_frame_host_routing_id. I know it is long, but I'd rather have the
"routing_id" more explicit.

[Charlie Reis, 2013/12/12 18:19:30]

That's a good idea.  We were using "frame_routing_id" for it in one place in
RFHM, so I used that here and in RFHM::Init.

+  // Initialize the RenderFrameHost for the new node.

[nasko, 2013/12/12 02:22:12]

Maybe add a note that when adding frames, they are *always* in the SiteInstance
of the parent. It is an invariant that is useful to know.

[Charlie Reis, 2013/12/12 18:19:30]

Done.

+  child->render_manager()->Init(
+      render_manager_.current_host()->GetSiteInstance()->GetBrowserContext(),
+      render_manager_.current_host()->GetSiteInstance(),
+      render_manager_.current_host()->GetRoutingID(),
+      render_frame_host_id);
   children_.push_back(child.release());
 }
 
 void FrameTreeNode::RemoveChild(FrameTreeNode* child) {
   std::vector<FrameTreeNode*>::iterator iter;
 
   for (iter = children_.begin(); iter != children_.end(); ++iter) {
     if ((*iter) == child)
       break;
   }
 
   if (iter != children_.end())
     children_.erase(iter);
 }
 
-void FrameTreeNode::ResetForMainFrame(
-    RenderFrameHostImpl* new_render_frame_host) {
-  owns_render_frame_host_ = false;
+void FrameTreeNode::ResetForMainFrameSwap() {
   frame_id_ = kInvalidFrameId;
   current_url_ = GURL();
 
   // The children may not have been cleared if a cross-process navigation
   // commits before the old process cleans everything up.  Make sure the child
   // nodes get deleted.
   children_.clear();
-
-  render_frame_host_ = new_render_frame_host;
 }
 
 }  // namespace content