[Web Payments] Fix some ScrollView issues in the dialog.

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

Index: chrome/browser/ui/views/payments/payment_request_sheet_controller.h
diff --git a/chrome/browser/ui/views/payments/payment_request_sheet_controller.h b/chrome/browser/ui/views/payments/payment_request_sheet_controller.h
index 666a0597d5a313874052c09f927526314be90382..5aa37b512029582340d3b2569b894555bb72f3cf 100644
--- a/chrome/browser/ui/views/payments/payment_request_sheet_controller.h
+++ b/chrome/browser/ui/views/payments/payment_request_sheet_controller.h
@@ -119,6 +119,10 @@ class PaymentRequestSheetController : public views::ButtonListener {
   views::View* pane_;
   views::View* content_view_;
 
+  // Hold on to the ScrollView because it must be explicitly laid out in some
+  // cases.
+  std::unique_ptr<views::ScrollView> scroll_;
+
   DISALLOW_COPY_AND_ASSIGN(PaymentRequestSheetController);
 };