Revert the fix for 538784.

content/browser/loader/cross_site_resource_handler.cc

Index: content/browser/loader/cross_site_resource_handler.cc
diff --git a/content/browser/loader/cross_site_resource_handler.cc b/content/browser/loader/cross_site_resource_handler.cc
index 0b9e6a77aa1f38a0dd34b668a1681bedc5d9fcbe..4539735733a149c27124d14ce2d0e71f5f4d57ae 100644
--- a/content/browser/loader/cross_site_resource_handler.cc
+++ b/content/browser/loader/cross_site_resource_handler.cc
@@ -96,8 +96,10 @@ CheckNavigationPolicyOnUI(GURL real_url, int process_id, int render_frame_id) {
   // Without a valid RFH against which to check, we must cancel the request,
   // to prevent the resource at |url| from being delivered to a potentially
   // unsuitable renderer process.
+  // TODO(nick): Switch this back to NavigationDecision::CANCEL once we fix
+  // existing transfer unittests that don't specify a valid rfh ID.
   if (!rfh)
-    return CrossSiteResourceHandler::NavigationDecision::CANCEL_REQUEST;
+    return CrossSiteResourceHandler::NavigationDecision::USE_EXISTING_RENDERER;
 
   RenderFrameHostManager* manager = rfh->frame_tree_node()->render_manager();
   if (manager->IsRendererTransferNeededForNavigation(rfh, real_url))