Allow top-level navigation in extension pop-ups if it only triggers a download.

content/browser/frame_host/navigation_request.cc

 // Copyright 2014 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/browser/frame_host/navigation_request.h"
 
 #include <utility>
 
 #include "content/browser/devtools/render_frame_devtools_agent_host.h"
 #include "content/browser/frame_host/frame_tree.h"
@@ skipping 341 matching lines @@
   // Select an appropriate renderer to commit the navigation.
   RenderFrameHostImpl* render_frame_host =
       frame_tree_node_->render_manager()->GetFrameHostForNavigation(*this);
   NavigatorImpl::CheckWebUIRendererDoesNotDisplayNormalURL(render_frame_host,
                                                            common_params_.url);
 
   // For renderer-initiated navigations that are set to commit in a different
   // renderer, allow the embedder to cancel the transfer.
   if (!browser_initiated_ &&
       render_frame_host != frame_tree_node_->current_frame_host() &&
-      !frame_tree_node_->navigator()
-           ->GetDelegate()
-           ->ShouldTransferNavigation()) {
+      !frame_tree_node_->navigator()->GetDelegate()->ShouldTransferNavigation(
+          frame_tree_node_->IsMainFrame())) {
     frame_tree_node_->ResetNavigationRequest(false);
     return;
   }
 
   if (navigation_data)
     navigation_handle_->set_navigation_data(std::move(navigation_data));
 
   // Store the response and the StreamHandle until checks have been processed.
   response_ = response;
   body_ = std::move(body);
@@ skipping 140 matching lines @@
 
   TransferNavigationHandleOwnership(render_frame_host);
   render_frame_host->CommitNavigation(response_.get(), std::move(body_),
                                       common_params_, request_params_,
                                       is_view_source_);
 
   frame_tree_node_->ResetNavigationRequest(true);
 }
 
 }  // namespace content