Adds a test that verifies that navigating in the unload handler while

content/renderer/render_frame_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/renderer/render_frame_impl.h"
 
 #include <map>
 #include <string>
 #include <utility>
 #include <vector>
@@ skipping 1668 matching lines @@
                                   base::IntToString(proxy->routing_id()));
     base::debug::SetCrashKeyValue(
         "swapout_view_id", base::IntToString(render_view->GetRoutingID()));
     CHECK(!render_view->main_render_frame_);
   }
 
   if (!success) {
     // The swap can fail when the frame is detached during swap (this can
     // happen while running the unload handlers). When that happens, delete
     // the proxy.
-    // TODO(lfg): Handle the case where a navigation started during swap.
-    // See https://crbug.com/590054 for more details.
     proxy->frameDetached(blink::WebRemoteFrameClient::DetachType::Swap);
     return;
   }
 
   if (is_loading)
     proxy->OnDidStartLoading();
 
   // Initialize the WebRemoteFrame with the replication state passed by the
   // process that is now rendering the frame.
   proxy->SetReplicatedState(replicated_frame_state);
@@ skipping 4650 matching lines @@
   // event target. Potentially a Pepper plugin will receive the event.
   // In order to tell whether a plugin gets the last mouse event and which it
   // is, we set |pepper_last_mouse_event_target_| to null here. If a plugin gets
   // the event, it will notify us via DidReceiveMouseEvent() and set itself as
   // |pepper_last_mouse_event_target_|.
   pepper_last_mouse_event_target_ = nullptr;
 #endif
 }
 
 }  // namespace content