<webview>: Make contentWindow available prior to attachment (on display:none).

extensions/browser/api/guest_view/guest_view_internal_api.cc

Index: extensions/browser/api/guest_view/guest_view_internal_api.cc
diff --git a/extensions/browser/api/guest_view/guest_view_internal_api.cc b/extensions/browser/api/guest_view/guest_view_internal_api.cc
index 6b700233ca89186644004b1eecb0c1e7b9c98d85..0b6f2f1a51efa8219e7a894cec5d2c91df84f306 100644
--- a/extensions/browser/api/guest_view/guest_view_internal_api.cc
+++ b/extensions/browser/api/guest_view/guest_view_internal_api.cc
@@ -9,6 +9,7 @@
 #include "extensions/browser/guest_view/guest_view_base.h"
 #include "extensions/browser/guest_view/guest_view_manager.h"
 #include "extensions/common/api/guest_view_internal.h"
+#include "extensions/common/guest_view/guest_view_constants.h"
 #include "extensions/common/permissions/permissions_data.h"
 
 namespace guest_view_internal = extensions::core_api::guest_view_internal;
@@ -53,11 +54,16 @@ bool GuestViewInternalCreateGuestFunction::RunAsync() {
 void GuestViewInternalCreateGuestFunction::CreateGuestCallback(
     content::WebContents* guest_web_contents) {
   int guest_instance_id = 0;
+  int content_window_id = MSG_ROUTING_NONE;
   if (guest_web_contents) {
     GuestViewBase* guest = GuestViewBase::FromWebContents(guest_web_contents);
     guest_instance_id = guest->guest_instance_id();
+    content_window_id = guest->proxy_host()->GetGuestProxyRoutingID();
   }
-  SetResult(new base::FundamentalValue(guest_instance_id));
+  scoped_ptr<base::DictionaryValue> return_params(new base::DictionaryValue());
+  return_params->SetInteger(guestview::kID, guest_instance_id);
+  return_params->SetInteger(guestview::kContentWindowID, content_window_id);
+  SetResult(return_params.release());
   SendResponse(true);
 }