Plumb opener information when creating RenderFrames and RenderFrameProxies for subframes.

content/renderer/render_frame_impl.cc

Index: content/renderer/render_frame_impl.cc
diff --git a/content/renderer/render_frame_impl.cc b/content/renderer/render_frame_impl.cc
index 594da3c38f9c518921d0056c547e8bcdfc02f722..a9f2a025ccd47ee13260d3bd0b3d6fc642124905 100644
--- a/content/renderer/render_frame_impl.cc
+++ b/content/renderer/render_frame_impl.cc
@@ -573,6 +573,7 @@ void RenderFrameImpl::CreateFrame(
     int parent_routing_id,
     int previous_sibling_routing_id,
     int proxy_routing_id,
+    int opener_routing_id,
     const FrameReplicationState& replicated_state,
     CompositorDependencies* compositor_deps,
     const FrameMsg_NewFrame_WidgetParams& widget_params) {
@@ -614,6 +615,9 @@ void RenderFrameImpl::CreateFrame(
   render_frame->SetWebFrame(web_frame);
   CHECK_IMPLIES(parent_routing_id == MSG_ROUTING_NONE, !web_frame->parent());
 
+  WebFrame* opener = ResolveOpener(opener_routing_id, nullptr);
+  web_frame->setOpener(opener);
+
   if (widget_params.routing_id != MSG_ROUTING_NONE) {
     CHECK(SiteIsolationPolicy::AreCrossProcessFramesPossible());
     render_frame->render_widget_ = RenderWidget::CreateForFrame(