Fix leaking of RenderFrames.

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 1693d1f77ba56e0899765c4c384cf8835c0c3484..7cb664f5347d8bd8d6b2eaf545f690bad94121eb 100644
--- a/content/renderer/render_frame_impl.cc
+++ b/content/renderer/render_frame_impl.cc
@@ -671,6 +671,13 @@ void RenderFrameImpl::CreateFrame(
 }
 
 // static
+void RenderFrameImpl::DetachFrame(int routing_id) {

[dcheng, 2015/11/03 04:22:54]

Is it worth DCHECKing our current limitations? For example, this shouldn't be
called on a main frame, right?

[nasko, 2015/11/03 17:59:08]

Done.

[Charlie Reis, 2015/11/04 21:28:30]

I don't see the new DCHECK.  I guess it doesn't apply now that we realized we
need to call it on main frames as well?

+  RenderFrameImpl* frame = RenderFrameImpl::FromRoutingID(routing_id);
+  frame->set_in_browser_initiated_detach();
+  frame->GetWebFrame()->detach();
+}
+
+// static
 RenderFrame* RenderFrame::FromWebFrame(blink::WebFrame* web_frame) {
   return RenderFrameImpl::FromWebFrame(web_frame);
 }
@@ -733,6 +740,7 @@ RenderFrameImpl::RenderFrameImpl(const CreateParams& params)
     : frame_(NULL),
       is_main_frame_(true),
       is_local_root_(false),
+      in_browser_initiated_detach_(false),
       render_view_(params.render_view->AsWeakPtr()),
       routing_id_(params.routing_id),
       is_swapped_out_(false),
@@ -2369,9 +2377,8 @@ void RenderFrameImpl::frameDetached(blink::WebFrame* frame, DetachType type) {
                     FrameDetached(frame));
 
   // We only notify the browser process when the frame is being detached for
-  // removal. If the frame is being detached for swap, we don't need to do this
-  // since we are not modifiying the frame tree.
-  if (type == DetachType::Remove)
+  // removal and it was initiated from the renderer process.
+  if (!in_browser_initiated_detach_ && type == DetachType::Remove)
     Send(new FrameHostMsg_Detach(routing_id_));
 
   // The |is_detaching_| flag disables Send(). FrameHostMsg_Detach must be
@@ -2394,10 +2401,18 @@ void RenderFrameImpl::frameDetached(blink::WebFrame* frame, DetachType type) {
   g_frame_map.Get().erase(it);
 
   // Only remove the frame from the renderer's frame tree if the frame is
-  // being detached for removal. In the case of a swap, the frame needs to
-  // remain in the tree so WebFrame::swap() can replace it with the new frame.
-  if (!is_main_frame_ && type == DetachType::Remove)
-    frame->parent()->removeChild(frame);
+  // being detached for removal and it is inserted in the set of child frames.
+  // In the case of a swap, the frame needs to remain in the tree so
+  // WebFrame::swap() can replace it with the new frame.
+  if (!is_main_frame_ && type == DetachType::Remove) {
+    for (WebFrame* child = frame->parent()->firstChild(); child;

[dcheng, 2015/11/03 04:22:53]

Is there no heuristic we can use inside //content itself? This check makes me
pretty sad.

[nasko, 2015/11/03 17:59:08]

Well, content/ is now in charge of maintaining the frame tree, right? So it is
in content/ that we check whether this frame has been linked into the frame
tree. I could start adding booleans to indicate different states, but I think
this is less prone to problems in the future. Also, it is easy to understand why
we aren't removing the frame from the parent - it isn't in its list of children.

If we have to do this in more than one place, I'm open to exploring storing
state or something else.

+         child = child->nextSibling()) {
+      if (child == frame) {
+        frame->parent()->removeChild(frame);
+        break;
+      }
+    }
+  }
 
   // |frame| is invalid after here.  Be sure to clear frame_ as well, since this
   // object may not be deleted immediately and other methods may try to access