Allow embedders to provide a custom view for popup (select box) widgets,

content/browser/web_contents/web_contents_impl.cc

Index: content/browser/web_contents/web_contents_impl.cc
===================================================================
--- content/browser/web_contents/web_contents_impl.cc	(revision 175506)
+++ content/browser/web_contents/web_contents_impl.cc	(working copy)
@@ -1394,8 +1394,10 @@
       new RenderWidgetHostImpl(this, process, route_id);
   created_widgets_.insert(widget_host);
 
-  RenderWidgetHostViewPort* widget_view =
-      RenderWidgetHostViewPort::CreateViewForWidget(widget_host);
+  RenderWidgetHostViewPort* widget_view = RenderWidgetHostViewPort::FromRWHV(
+      view_->CreateViewForPopupWidget(widget_host));
+  if (!widget_view)
+    return;
   if (!is_fullscreen) {
     // Popups should not get activated.
     widget_view->SetPopupType(popup_type);