Destroy the old RenderWidgetHostView when swapping out a main frame.

content/browser/renderer_host/render_view_host_impl.h

Index: content/browser/renderer_host/render_view_host_impl.h
diff --git a/content/browser/renderer_host/render_view_host_impl.h b/content/browser/renderer_host/render_view_host_impl.h
index 8990af9160500b1af96c3db719dfc49e465d6f6f..bb1049edd2052dc5167bb8419254e8d2faa0e7dd 100644
--- a/content/browser/renderer_host/render_view_host_impl.h
+++ b/content/browser/renderer_host/render_view_host_impl.h
@@ -170,6 +170,7 @@ class CONTENT_EXPORT RenderViewHostImpl : public RenderViewHost,
 
   // Tracks whether this RenderViewHost is swapped out, according to its main
   // frame RenderFrameHost.
+  bool is_swapped_out() { return is_swapped_out_; }

[Charlie Reis, 2016/11/15 19:59:05]

Hmm, I think we should be working to remove is_swapped_out_ (per the TODO on
line 330) rather than adding calls to it.  Is this turning into a concept we
need long term, or are there ways we can avoid using it?

[lfg, 2016/11/23 00:27:04]

Removed in favor of using is_active.

   void set_is_swapped_out(bool is_swapped_out) {
     is_swapped_out_ = is_swapped_out;
   }