[Web Payments] Add Cancel button to all sheets

chrome/browser/ui/views/payments/payment_request_views_util.h

Index: chrome/browser/ui/views/payments/payment_request_views_util.h
diff --git a/chrome/browser/ui/views/payments/payment_request_views_util.h b/chrome/browser/ui/views/payments/payment_request_views_util.h
index 13e250614e9a4e19fa1678f90432b847426be79c..b00c97244b29559ae1d0499ec0d4d30bc6925998 100644
--- a/chrome/browser/ui/views/payments/payment_request_views_util.h
+++ b/chrome/browser/ui/views/payments/payment_request_views_util.h
@@ -50,18 +50,21 @@ std::unique_ptr<views::View> CreateSheetHeaderView(
 // |header_view| is the view displayed on top of the dialog, containing title,
 // (optional) back button, and close buttons.
 // |content_view| is displayed between |header_view| and the pay/cancel buttons.
-// The returned view takes ownership of |header_view| and |content_view|.
+// |buttons_view| is clamped to the bottom of the containing view.
+// The returned view takes ownership of |header_view|, |content_view|, and
+// |buttons_view|.
 // +---------------------------+
 // |        HEADER VIEW        |
 // +---------------------------+
 // |          CONTENT          |
 // |           VIEW            |
 // +---------------------------+
-// |            | CANCEL | PAY |
+// |            | CANCEL | PAY | <-- |buttons_view|
 // +---------------------------+
 std::unique_ptr<views::View> CreatePaymentView(
     std::unique_ptr<views::View> header_view,
-    std::unique_ptr<views::View> content_view);
+    std::unique_ptr<views::View> content_view,
+    std::unique_ptr<views::View> buttons_view);
 
 // Represents formatting options for each of the different contexts in which an
 // Address label may be displayed.