Propagate opener to BackgroundsContents.

chrome/browser/chromeos/first_run/drive_first_run_controller.cc

Index: chrome/browser/chromeos/first_run/drive_first_run_controller.cc
diff --git a/chrome/browser/chromeos/first_run/drive_first_run_controller.cc b/chrome/browser/chromeos/first_run/drive_first_run_controller.cc
index b69a68859675b7daa28a7ffcdd0944ccd015f911..dbcb75080f0429e94d1db3ebcb7a955118f06e09 100644
--- a/chrome/browser/chromeos/first_run/drive_first_run_controller.cc
+++ b/chrome/browser/chromeos/first_run/drive_first_run_controller.cc
@@ -163,6 +163,7 @@ class DriveWebContentsManager : public content::WebContentsObserver,
   // content::WebContentsDelegate overrides:
   bool ShouldCreateWebContents(
       content::WebContents* web_contents,
+      content::RenderFrameHost* opener,
       content::SiteInstance* source_site_instance,
       int32_t route_id,
       int32_t main_frame_route_id,
@@ -276,6 +277,7 @@ void DriveWebContentsManager::DidFailLoad(
 
 bool DriveWebContentsManager::ShouldCreateWebContents(
     content::WebContents* web_contents,
+    content::RenderFrameHost* opener,
     content::SiteInstance* source_site_instance,
     int32_t route_id,
     int32_t main_frame_route_id,
@@ -310,7 +312,7 @@ bool DriveWebContentsManager::ShouldCreateWebContents(
   // so we must not use |route_id|, etc, which are IDs in a different process.
   BackgroundContents* contents =
       background_contents_service->CreateBackgroundContents(
-          content::SiteInstance::Create(profile_), MSG_ROUTING_NONE,
+          content::SiteInstance::Create(profile_), nullptr, MSG_ROUTING_NONE,

[Andrew T Wilson (Slow), 2017/06/05 08:32:46]

I'm not sure why we are passing in nullptr here instead of opener - maybe this
is worth a comment?

[Łukasz Anforowicz, 2017/06/05 16:57:56]

Good point - this is not that obvious what is going on here.  If you look at
Browser::MaybeCreateBackgroundContents, then it has 2 calls to
CreateBackgroundContents - one where the opener is propagated, and one where no
opener is propagated (and where MSG_ROUTING_NONE are passed, because [since
we're not establishing an opener relationship] we don't care to create the new
contents in the same renderer process as the opener).  Here we also need the
second case, because (just like the second case in
Browser::MaybeCreateBackgroundContents) here also we have allow_js_access:false
(i.e. see chrome/test/data/drive_first_run/app/manifest.json) that corresponds
to the MSG_ROUTING_NONE usage.

I've added a comment.

           MSG_ROUTING_NONE, MSG_ROUTING_NONE, profile_, frame_name,
           base::ASCIIToUTF16(app_id_), partition_id, session_storage_namespace);