iframes with allowpaymentrequest attribute are allowed to make payment requests.

third_party/WebKit/Source/web/WebLocalFrameImpl.cpp

 /*
  * Copyright (C) 2009 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 1608 matching lines @@
     const AtomicString& name,
     HTMLFrameOwnerElement* ownerElement) {
   DCHECK(m_client);
   TRACE_EVENT0("blink", "WebLocalFrameImpl::createChildframe");
   WebTreeScopeType scope = frame()->document() == ownerElement->treeScope()
                                ? WebTreeScopeType::Document
                                : WebTreeScopeType::Shadow;
   WebFrameOwnerProperties ownerProperties(
       ownerElement->scrollingMode(), ownerElement->marginWidth(),
       ownerElement->marginHeight(), ownerElement->allowFullscreen(),
-      ownerElement->csp(), ownerElement->delegatedPermissions());
+      ownerElement->allowFullscreen(), ownerElement->csp(),

[please use gerrit instead, 2016/10/17 13:57:48]

You seem to have passed in "allowFullscreen()" twice. One of these should be
"allowPaymentRequest()". Right?

[pals, 2016/10/18 04:39:21]

Its a mistake. Messed up during rebase from patch set 2 to patch set 3.
Corrected now.

+      ownerElement->delegatedPermissions());
   // FIXME: Using subResourceAttributeName as fallback is not a perfect
   // solution. subResourceAttributeName returns just one attribute name. The
   // element might not have the attribute, and there might be other attributes
   // which can identify the element.
   AtomicString uniqueName = frame()->tree().calculateUniqueNameForNewChildFrame(
       name,
       ownerElement->getAttribute(ownerElement->subResourceAttributeName()));
   WebLocalFrameImpl* webframeChild =
       toWebLocalFrameImpl(m_client->createChildFrame(
           this, scope, name, uniqueName,
@@ skipping 732 matching lines @@
     feature = UseCounter::ChromeLoadTimesNpnNegotiatedProtocol;
   } else if (metric == "wasAlternateProtocolAvailable") {
     feature = UseCounter::ChromeLoadTimesWasAlternateProtocolAvailable;
   } else if (metric == "connectionInfo") {
     feature = UseCounter::ChromeLoadTimesConnectionInfo;
   }
   UseCounter::count(frame(), feature);
 }
 
 }  // namespace blink