PlzNavigate: allow the embedder to cancel a transferring navigation

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 293 matching lines @@
     common_params_.lofi_state = LOFI_ON;
   else
     common_params_.lofi_state = LOFI_OFF;
 
   // 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_->ResetNavigationRequest(false);
+    return;
+  }
+
   // Store the response and the StreamHandle until checks have been processed.
   response_ = response;
   body_ = std::move(body);
 
   // Check if the navigation should be allowed to proceed.
   navigation_handle_->WillProcessResponse(
       render_frame_host, response->head.headers.get(),
       base::Bind(&NavigationRequest::OnWillProcessResponseChecksComplete,
                  base::Unretained(this)));
 }
@@ skipping 119 matching lines @@
       browser_context, navigating_frame_host->GetSiteInstance());
   DCHECK(partition);
 
   ServiceWorkerContextWrapper* service_worker_context =
       static_cast<ServiceWorkerContextWrapper*>(
           partition->GetServiceWorkerContext());
   navigation_handle_->InitServiceWorkerHandle(service_worker_context);
 }
 
 }  // namespace content