RenderWidget popup should be a NSWindow so it can go outside the main window.

content/browser/renderer_host/render_widget_host_view_guest.cc

Index: content/browser/renderer_host/render_widget_host_view_guest.cc
diff --git a/content/browser/renderer_host/render_widget_host_view_guest.cc b/content/browser/renderer_host/render_widget_host_view_guest.cc
index b9adaffaaaea3e410c6ec42f5ffed2e03377e154..58367a30a560098e14cd7f0356ddb5e57ad4f436 100644
--- a/content/browser/renderer_host/render_widget_host_view_guest.cc
+++ b/content/browser/renderer_host/render_widget_host_view_guest.cc
@@ -107,7 +107,8 @@ void RenderWidgetHostViewGuest::InitAsChild(
 }
 
 void RenderWidgetHostViewGuest::InitAsPopup(
-    RenderWidgetHostView* parent_host_view, const gfx::Rect& pos) {
+    RenderWidgetHostView* parent_host_view, const gfx::Rect& pos,
+    WebContentsViewDelegate*) {
   NOTIMPLEMENTED();
 }