Fix leaking of RenderFrames.

content/browser/frame_host/render_frame_host_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/render_frame_host_impl.h"
 
 #include "base/bind.h"
 #include "base/command_line.h"
 #include "base/containers/hash_tables.h"
 #include "base/lazy_instance.h"
@@ skipping 221 matching lines @@
 }
 
 RenderFrameHostImpl::~RenderFrameHostImpl() {
   GetProcess()->RemoveRoute(routing_id_);
   g_routing_id_frame_map.Get().erase(
       RenderFrameHostID(GetProcess()->GetID(), routing_id_));
 
   if (delegate_ && render_frame_created_)
     delegate_->RenderFrameDeleted(this);
 
-  // If this was swapped out, it already decremented the active frame count of
-  // the SiteInstance it belongs to.
-  if (IsRFHStateActive(rfh_state_))
+  if (IsRFHStateActive(rfh_state_)) {
+    // If this was swapped out, it already decremented the active frame count of
+    // the SiteInstance it belongs to.
     GetSiteInstance()->decrement_active_frame_count();
 
+    // In the case of swapping with a RenderFrameProxy, cleanup is already
+    // handled on the renderer process side. However, in all other cases the
+    // corresponding RenderFrame also needs to be cleaned up.

[nasko, 2015/10/29 23:55:38]

I'm not correct here. The case of main frame and same site subframe, where the
main frame removes the subframe from the tree. It will result in a detach
message from the RenderFrame, which the renderer will cleanup right after the
IPC is sent.

In that case, we will send an extra IPC that will not have a listener, so it
shouldn't really be a problem, but I still dislike it. I will think of how to
fix this tomorrow, though the strawman is to add DETACHED state into rfh_state_,
which we set in the FrameHostMsg_Detach and handle properly here.

+    if (render_frame_created_)
+      Send(new FrameMsg_Detach(routing_id_));
+  }
+
   // NULL out the swapout timer; in crash dumps this member will be null only if
   // the dtor has run.
   swapout_event_monitor_timeout_.reset();
 
   for (const auto& iter: visual_state_callbacks_) {
     iter.second.Run(false);
   }
 
   if (render_widget_host_ &&
       render_widget_host_->owned_by_render_frame_host()) {
@@ skipping 2036 matching lines @@
   *dst = src;
 
   if (src.routing_id != -1)
     dst->tree_id = RoutingIDToAXTreeID(src.routing_id);
 
   if (src.parent_routing_id != -1)
     dst->parent_tree_id = RoutingIDToAXTreeID(src.parent_routing_id);
 }
 
 }  // namespace content