Detach old frame on WebFrame::swap.

content/renderer/render_frame_impl.cc

Index: content/renderer/render_frame_impl.cc
diff --git a/content/renderer/render_frame_impl.cc b/content/renderer/render_frame_impl.cc
index 5beb236fb01e24e24536d64345cf2d6ab14b078b..3f288089381866f5c04e382c02be2966d7d85351 100644
--- a/content/renderer/render_frame_impl.cc
+++ b/content/renderer/render_frame_impl.cc
@@ -692,7 +692,7 @@ RenderFrameImpl::~RenderFrameImpl() {
     if (render_frame_proxy_) {
       // The following method calls back into this object and clears
       // |render_frame_proxy_|.
-      render_frame_proxy_->frameDetached();
+      render_frame_proxy_->frameDetached(false);

[dcheng, 2015/05/28 21:56:00]

I don't understand the comment or this code. Why do we need to do this?

[lfg, 2015/05/29 18:34:44]

This code is needed to destroy the RenderFrameProxy for a swapped out
RenderFrameImpl. Should be removed soon when nasko@ is able to remove the
swapped out RF/RV.

     }
 
     // Ensure the RenderView doesn't point to this object, once it is destroyed.
@@ -2120,6 +2120,11 @@ void RenderFrameImpl::didDisownOpener(blink::WebLocalFrame* frame) {
 }
 
 void RenderFrameImpl::frameDetached(blink::WebFrame* frame) {
+  frameDetached(frame, false);
+}
+
+void RenderFrameImpl::frameDetached(blink::WebFrame* frame,
+                                    bool for_replacement) {
   // NOTE: This function is called on the frame that is being detached and not
   // the parent frame.  This is different from createChildFrame() which is
   // called on the parent frame.
@@ -2130,7 +2135,8 @@ void RenderFrameImpl::frameDetached(blink::WebFrame* frame) {
   FOR_EACH_OBSERVER(RenderViewObserver, render_view_->observers(),
                     FrameDetached(frame));
 
-  Send(new FrameHostMsg_Detach(routing_id_));
+  if (!for_replacement)
+    Send(new FrameHostMsg_Detach(routing_id_));
 
   // The |is_detaching_| flag disables Send(). FrameHostMsg_Detach must be
   // sent before setting |is_detaching_| to true.
@@ -2150,7 +2156,9 @@ void RenderFrameImpl::frameDetached(blink::WebFrame* frame) {
             switches::kSitePerProcess) && render_widget_) {
       render_widget_->UnregisterRenderFrame(this);
     }
-    frame->parent()->removeChild(frame);
+
+    if (!for_replacement)
+      frame->parent()->removeChild(frame);
   }
 
   // |frame| is invalid after here.  Be sure to clear frame_ as well, since this