[Web Payments] Add "pencil" edit button to lists.

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

Index: chrome/browser/ui/views/payments/payment_request_item_list.h
diff --git a/chrome/browser/ui/views/payments/payment_request_item_list.h b/chrome/browser/ui/views/payments/payment_request_item_list.h
index dee0a8a6855489b2f651e075e9ef95d4769a55e2..2673ecc26bb98e199e3d8b22fd8fc91e42640d38 100644
--- a/chrome/browser/ui/views/payments/payment_request_item_list.h
+++ b/chrome/browser/ui/views/payments/payment_request_item_list.h
@@ -12,6 +12,7 @@
 #include "ui/views/controls/button/button.h"
 
 namespace views {
+class ImageButton;
 class ImageView;
 class View;
 }
@@ -36,7 +37,8 @@ class PaymentRequestItemList {
     Item(PaymentRequestSpec* spec,
          PaymentRequestState* state,
          PaymentRequestItemList* list,
-         bool selected);
+         bool selected,
+         bool show_edit_button);
     ~Item() override;
 
     // Gets the view associated with this item. It's owned by this object so
@@ -89,6 +91,10 @@ class PaymentRequestItemList {
     // false. This will usually be to display an editor.
     virtual void PerformSelectionFallback() = 0;
 
+    // Called when the edit button is pressed. Subclasses should open the editor
+    // appropriate for the item they represent.
+    virtual void EditButtonPressed() = 0;
+
    private:
     // Creates and returns the view associated with this list item.
     std::unique_ptr<views::View> CreateItemView();
@@ -101,7 +107,9 @@ class PaymentRequestItemList {
     PaymentRequestState* state_;
     PaymentRequestItemList* list_;
     std::unique_ptr<views::ImageView> checkmark_;
+    std::unique_ptr<views::ImageButton> edit_button_;

[sky, 2017/05/12 01:28:48]

I think a better approach here is to not have the member at all. Instead use a
tag or id on the button to identify in the listener.

     bool selected_;
+    bool show_edit_button_;
 
     DISALLOW_COPY_AND_ASSIGN(Item);
   };