Move blocking of top-level navigations to nested URLs with extension origins from non-extension pro…

content/browser/frame_host/navigation_handle_impl.cc

Index: content/browser/frame_host/navigation_handle_impl.cc
diff --git a/content/browser/frame_host/navigation_handle_impl.cc b/content/browser/frame_host/navigation_handle_impl.cc
index b0f6efe4efab876abe3faade52850886b9d2f0b9..b0cb4288bde83f41816c0223889f9941aff8f527 100644
--- a/content/browser/frame_host/navigation_handle_impl.cc
+++ b/content/browser/frame_host/navigation_handle_impl.cc
@@ -91,6 +91,10 @@ NavigationHandleImpl::NavigationHandleImpl(
       weak_factory_(this) {
   DCHECK(!navigation_start.is_null());
   redirect_chain_.push_back(url);
+
+  starting_site_instance_ =
+      frame_tree_node_->current_frame_host()->GetSiteInstance();
+
   GetDelegate()->DidStartNavigation(this);
 
   if (IsInMainFrame()) {
@@ -128,6 +132,10 @@ const GURL& NavigationHandleImpl::GetURL() {
   return url_;
 }
 
+SiteInstance* NavigationHandleImpl::GetStartingSiteInstance() {
+  return starting_site_instance_.get();
+}
+
 bool NavigationHandleImpl::IsInMainFrame() {
   return frame_tree_node_->IsMainFrame();
 }