Destroy the old RenderWidgetHostView when swapping out a main frame.

content/browser/renderer_host/render_view_host_impl.h

 // Copyright (c) 2012 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.
 
 #ifndef CONTENT_BROWSER_RENDERER_HOST_RENDER_VIEW_HOST_IMPL_H_
 #define CONTENT_BROWSER_RENDERER_HOST_RENDER_VIEW_HOST_IMPL_H_
 
 #include <stddef.h>
 #include <stdint.h>
 
@@ skipping 152 matching lines @@
   }
 
   // Tracks whether this RenderViewHost is in an active state (rather than
   // pending swap out or swapped out), according to its main frame
   // RenderFrameHost.
   bool is_active() const { return is_active_; }
   void set_is_active(bool is_active) { is_active_ = is_active; }
 
   // 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;
   }
 
   // TODO(creis): Remove as part of http://crbug.com/418265.
   bool is_waiting_for_close_ack() const { return is_waiting_for_close_ack_; }
 
   // Tells the renderer process to run the page's unload handler.
   // A ClosePage_ACK ack is sent back when the handler execution completes.
   void ClosePage();
@@ skipping 173 matching lines @@
   bool render_view_ready_on_process_launch_;
 
   base::WeakPtrFactory<RenderViewHostImpl> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(RenderViewHostImpl);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_RENDERER_HOST_RENDER_VIEW_HOST_IMPL_H_