Service worker bypass for resource requests from suborigins

third_party/WebKit/Source/core/loader/FrameFetchContext.cpp

 /*
  * Copyright (C) 2013 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 576 matching lines @@
     DocumentLoader* documentLoader = masterDocumentLoader();
     if (documentLoader && documentLoader->subresourceFilter() && type != Resource::MainResource && type != Resource::ImportResource && !documentLoader->subresourceFilter()->allowLoad(url, resourceRequest.requestContext()))
         return ResourceRequestBlockedReasonSubresourceFilter;
 
     return ResourceRequestBlockedReasonNone;
 }
 
 bool FrameFetchContext::isControlledByServiceWorker() const
 {
     ASSERT(m_documentLoader || frame()->loader().documentLoader());
+
+    if (getSecurityOrigin() && getSecurityOrigin()->hasSuborigin())
+        return false;

[falken, 2016/09/20 04:52:52]

OK the rationale for allowing .controller makes sense. But it's not obvious to
me why we need this code, I'd naively expect the setSkipServiceWorker() call to
do everything. Was this needed for the mem cache thing? Can you add a brief
comment about that?

[jww, 2016/09/20 17:52:26]

Yes, it was needed for the mem cache bit. Otherwise, when the mem cache ID is
reached for, if this returns true, it will set the mem cache id to be that of
the service worker controller (and thus return any resources cached by the
service worker, which is bad since we want to bypass the service worker for
suborigins). See ResourceFetcher::getCacheIdentifier() to see where this occurs.

Adding a comment to clarify all of this.

+
     if (m_documentLoader)
         return frame()->loader().client()->isControlledByServiceWorker(*m_documentLoader);
     // m_documentLoader is null while loading resources from an HTML import.
     // In such cases whether the request is controlled by ServiceWorker or not
     // is determined by the document loader of the frame.
     return frame()->loader().client()->isControlledByServiceWorker(*frame()->loader().documentLoader());
 }
 
 int64_t FrameFetchContext::serviceWorkerID() const
 {
@@ skipping 192 matching lines @@
 }
 
 DEFINE_TRACE(FrameFetchContext)
 {
     visitor->trace(m_document);
     visitor->trace(m_documentLoader);
     FetchContext::trace(visitor);
 }
 
 } // namespace blink