WebNavigationEventRouter::Retargeting uses RetargetingDetails::source_render_frame_id, but matches it up with details->source_web_contents->GetRenderProcessHost()->GetID(). That's the process ID for the main frame, which is wrong if the source RFH is an out-of-process iframe.
Nasko, can you help fix, since it's in the Web Navigation API? We probably need to add the source_render_process_id to RetargetingDetails, unless we want to go further and remove NOTIFICATION_RETARGETING in favor of WebContentsObserver::DidOpenRequestedURL().
Comment 1 by a...@chromium.org
, Sep 23 2016