PaymentHandler: Implement requestPermission().

components/payments_strings.grdp

Index: components/payments_strings.grdp
diff --git a/components/payments_strings.grdp b/components/payments_strings.grdp
index 40cf5f4a7b0f65a3810f7431dd73b9bef1af72bb..6f438f0f7091b525e5d24db4215e1fc15535e48a 100644
--- a/components/payments_strings.grdp
+++ b/components/payments_strings.grdp
@@ -310,6 +310,11 @@
     </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]">