PaymentHandler: Implement requestPermission().

components/content_settings/core/common/content_settings_types.h

Index: components/content_settings/core/common/content_settings_types.h
diff --git a/components/content_settings/core/common/content_settings_types.h b/components/content_settings/core/common/content_settings_types.h
index 24bd04b60f7da82207a94e08d243ccd07cc3eeef..5201e2a37784266170a864fa36ace051b03197d8 100644
--- a/components/content_settings/core/common/content_settings_types.h
+++ b/components/content_settings/core/common/content_settings_types.h
@@ -67,6 +67,9 @@ enum ContentSettingsType {
   // verdicts of each origin.
   CONTENT_SETTINGS_TYPE_PASSWORD_PROTECTION,
 
+  // This content setting type is whether to allow installing a payment handler.
+  CONTENT_SETTINGS_TYPE_PAYMENT_HANDLER,
+
   // WARNING: This enum is going to be removed soon. Do not depend on NUM_TYPES.
   CONTENT_SETTINGS_NUM_TYPES_DO_NOT_USE,
 };