Enable PaymentRequest on Android by default.

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 31d7aefcd42a438a13aaf29edcb7ea011fb83365..d5ff3f88f2627be299d8a9d214302e17dbdf0f11 100644
--- a/content/public/common/content_features.cc
+++ b/content/public/common/content_features.cc
@@ -154,6 +154,11 @@ const base::Feature kImeThread{"ImeThread", base::FEATURE_DISABLED_BY_DEFAULT};
 // FeatureList definition for the Seccomp field trial.
 const base::Feature kSeccompSandboxAndroid{"SeccompSandboxAndroid",
                                            base::FEATURE_DISABLED_BY_DEFAULT};
+
+// The JavaScript API for payments on the web.
+const base::Feature kWebPayments{"WebPayments",
+                                 base::FEATURE_ENABLED_BY_DEFAULT};
+
 #endif
 
 #if defined(OS_WIN)