PaymentApp: Add classes for supporting Web Based Payment Apps

content/public/common/content_features.cc

Index: content/public/common/content_features.cc
diff --git a/content/public/common/content_features.cc b/content/public/common/content_features.cc
index 0933f2385fcdafc613c528d84f03907176d21de3..2ac1636a80432165a3a12a6b94393cfc9a302a2e 100644
--- a/content/public/common/content_features.cc
+++ b/content/public/common/content_features.cc
@@ -247,6 +247,12 @@ const base::Feature kImeThread{"ImeThread", base::FEATURE_ENABLED_BY_DEFAULT};
 const base::Feature kSeccompSandboxAndroid{"SeccompSandboxAndroid",
                                            base::FEATURE_DISABLED_BY_DEFAULT};
 
+// Service worker based payment apps as defined by w3c here:
+// https://w3c.github.io/webpayments-payment-apps-api/
+const base::Feature kServiceWorkerPaymentApps{
+    "ServiceWorkerPaymentApps",
+    base::FEATURE_DISABLED_BY_DEFAULT};
+
 // The JavaScript API for payments on the web.
 const base::Feature kWebPayments{"WebPayments",
                                  base::FEATURE_ENABLED_BY_DEFAULT};