iframes with allowpaymentrequest attribute are allowed to make payment requests.

third_party/WebKit/Source/modules/payments/HTMLIFrameElementPayments.h

Index: third_party/WebKit/Source/modules/payments/HTMLIFrameElementPayments.h
diff --git a/third_party/WebKit/Source/modules/payments/HTMLIFrameElementPayments.h b/third_party/WebKit/Source/modules/payments/HTMLIFrameElementPayments.h
new file mode 100644
index 0000000000000000000000000000000000000000..0d78d608be72f6664fe2cf5235d0301f03825839
--- /dev/null
+++ b/third_party/WebKit/Source/modules/payments/HTMLIFrameElementPayments.h
@@ -0,0 +1,39 @@
+// Copyright 2016 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef HTMLIFrameElementPayments_h
+#define HTMLIFrameElementPayments_h
+
+#include "platform/Supplementable.h"
+#include "platform/heap/Handle.h"
+
+namespace blink {
+
+class HTMLIFrameElement;
+class QualifiedName;
+
+class HTMLIFrameElementPayments final
+    : public GarbageCollected<HTMLIFrameElementPayments>,
+      public Supplement<HTMLIFrameElement> {
+  USING_GARBAGE_COLLECTED_MIXIN(HTMLIFrameElementPayments);
+
+ public:
+  static bool fastHasAttribute(const QualifiedName&, const HTMLIFrameElement&);
+  static void setBooleanAttribute(const QualifiedName&,
+                                  HTMLIFrameElement&,
+                                  bool);
+  static HTMLIFrameElementPayments& from(HTMLIFrameElement&);
+  static bool allowPaymentRequest(HTMLIFrameElement&);
+
+  DECLARE_VIRTUAL_TRACE();
+
+ private:
+  HTMLIFrameElementPayments();
+
+  static const char* supplementName();
+};
+
+}  // namespace blink
+
+#endif  // HTMLIFrameElementPayments_h