PaymentHandler: Implement requestPermission().

components/payments_strings.grdp

 <?xml version="1.0" encoding="utf-8"?>
 <grit-part>
 
   <message name="IDS_PAYMENTS_TITLE" desc="Title of the dialog that presents a request for payment for some good or service [Desktop and iOS only].">
     Your Payment
   </message>
   <message name="IDS_PAYMENTS_NAME_FIELD_IN_CONTACT_DETAILS" desc="The label for text input field containing the full name of a person. [CHAR-LIMIT=32]" formatter_data="android_java">
     Name
   </message>
   <message name="IDS_PAYMENTS_PHONE_FIELD_IN_CONTACT_DETAILS" desc="The label for text input field containing a phone number. [CHAR-LIMIT=32]">
@@ skipping 292 matching lines @@
 
   <message name="IDS_UTILITY_PROCESS_PAYMENT_MANIFEST_PARSER_NAME" desc="The name of the utility process used for parsing payment manifest files.">
     Payment Manifest Parser
   </message>
   <if expr="is_android">
     <message name="IDS_EXTERNAL_PAYMENT_APP_LEAVE_INCOGNITO_WARNING" desc="Alert dialog text warning the user that incognito mode does not continue into external payment apps." formatter_data="android_java">
       Leaving incognito mode to pay via an external application. Continue?
     </message>
   </if>
 
+  <!-- PaymentHandler API -->
+  <message name="IDS_PAYMENTS_PAYMENT_HANDLER_REQUEST_PERMISSION" desc="requestPermission">
+    Chromium needs permission to install a new payment app provided from this site.
+  </message>
+
   <!-- Payment Request section preview strings. They are slightly different on desktop and android because the pluralization and formatting code behaves differently. -->
   <if expr="not is_android">
     <message name="IDS_PAYMENT_REQUEST_PAYMENT_METHODS_PREVIEW" desc="This is a snippet of a payment method a user has saved to Chrome, plus an indication of the number of additional payment methods the user has saved. Its function is to show the user has payment methods that can be used to complete a payment, and thus doesn't have to type the entire payment method. [ICU Syntax]">
     {PAYMENT_METHOD, plural,
        =0 {<ph name="PAYMENT_METHOD_PREVIEW">{1}<ex>VISA ....1234</ex></ph>}
        =1 {<ph name="PAYMENT_METHOD_PREVIEW">{1}<ex>VISA ....1234</ex></ph> and <ph name="NUMBER_OF_ADDITIONAL_PAYMENT_METHODS">{2}<ex>1</ex></ph> more}
        other {<ph name="PAYMENT_METHOD_PREVIEW">{1}<ex>VISA ....1234</ex></ph> and <ph name="NUMBER_OF_ADDITIONAL_PAYMENT_METHODS">{2}<ex>2</ex></ph> more}}
     </message>
     <message name="IDS_PAYMENT_REQUEST_SHIPPING_ADDRESSES_PREVIEW" desc="This is a snippet of a shipping address a user has saved to Chrome, plus an indication of the number of additional shipping addresses the user has saved. Its function is to show the user has shipping addresses that can be used to complete a purchase, and thus doesn't have to type the entire address. [ICU Syntax]" formatter_data="android_java">
     {SHIPPING_ADDRESS, plural,
@@ skipping 22 matching lines @@
   <message name="IDS_PAYMENTS_EDIT" desc="The screen reader string for the pencil edit button in the Desktop Payments dialog">
     Edit
   </message>
   <message name="IDS_PAYMENTS_ROW_ACCESSIBLE_NAME_FORMAT" desc="The format to build the screen reader string for Payment Sheet rows">
     <ph name="ROW_NAME">$1<ex>Payment Method</ex></ph> <ph name="ROW_CONTENT">$2<ex>VISA ****1234</ex></ph>
   </message>
   <message name="IDS_PAYMENTS_PROFILE_LABELS_ACCESSIBLE_FORMAT" desc="The format to build the screen reader string for profile labels">
     <ph name="FIRST_LABEL">$1<ex>VISA ****1234</ex></ph> <ph name="SECOND_LABEL">$2<ex>Homer Simpson</ex></ph> <ph name="THIRD_LABEL">$3<ex>123 Fake Street</ex></ph>
   </message>
 </grit-part>