Gate web payments iframe support on runtime enabled feature.

third_party/WebKit/Source/modules/payments/PaymentRequest.cpp

 // 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.
 
 #include "modules/payments/PaymentRequest.h"
 
 #include "bindings/core/v8/ExceptionState.h"
 #include "bindings/core/v8/ScriptPromiseResolver.h"
 #include "bindings/core/v8/ScriptState.h"
 #include "bindings/core/v8/V8StringResource.h"
@@ skipping 464 matching lines @@
 
   // 2. If |document|'s browsing context is a top-level browsing context, then
   // return true.
   if (frame->isMainFrame())
     return true;
 
   // 3. If |document|'s browsing context has a browsing context container that
   // is an iframe element with an |allowpaymentrequest| attribute specified, and
   // whose node document is allowed to use the feature indicated by
   // |allowpaymentrequest|, then return true.
-  if (frame->owner() && frame->owner()->allowPaymentRequest())
+  if (RuntimeEnabledFeatures::paymentRequestIFrameEnabled() && frame->owner() &&
+      frame->owner()->allowPaymentRequest()) {
     return allowedToUsePaymentRequest(frame->tree().parent());
+  }
 
   // 4. Return false.
   return false;
 }
 
 }  // namespace
 
 PaymentRequest* PaymentRequest::create(
     Document& document,
     const HeapVector<PaymentMethodData>& methodData,
@@ skipping 415 matching lines @@
   m_completeResolver.clear();
   m_showResolver.clear();
   m_abortResolver.clear();
   m_canMakePaymentResolver.clear();
   if (m_clientBinding.is_bound())
     m_clientBinding.Close();
   m_paymentProvider.reset();
 }
 
 }  // namespace blink