[Web Payments] Implement the credit card selection UI functionality.

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 71f4c04812d6eb0903b96538f6c6f5dab4fb23ab..167d38627113019774de9f69d773b78b518e6932 100644
--- a/chrome/browser/ui/views/payments/payment_request_item_list.h
+++ b/chrome/browser/ui/views/payments/payment_request_item_list.h
@@ -19,14 +19,16 @@ namespace payments {
 // A control representing a list of selectable items in the PaymentRequest
 // dialog. These lists enforce that only one of their elements be selectable at
 // a time and that "incomplete" items (for example, a credit card with no known
-// expriration date) behave differently when selected. Most of the time, this
+// expiration date) behave differently when selected. Most of the time, this
 // behavior is to show an editor screen.
 class PaymentRequestItemList {
  public:
   // Represents an item in the item list.
   class Item {
    public:
-    Item();
+    // Creates an item that will be owned by |list| with the initial state set
+    // to |selected|.
+    Item(PaymentRequestItemList* list, bool selected);
     virtual ~Item();
 
     // Gets the view associated with this item. It's owned by this object so
@@ -34,12 +36,27 @@ class PaymentRequestItemList {
     // view.
     views::View* GetItemView();
 
+    bool selected() const { return selected_; }
+    // Changes the selected state of this item to |selected| and calls
+    // SelectedStateChanged.
+    void set_selected(bool selected);

[Mathieu, 2017/02/23 21:22:53]

nit: If it has side effects it probably needs to be CamelCased

[anthonyvd, 2017/02/23 21:49:20]

Good point, done.

+
+    // Returns a pointer to the PaymentRequestItemList that owns this object.
+    PaymentRequestItemList* list() { return list_; }
+
    protected:
     // Creates and returns the view associated with this list item.
     virtual std::unique_ptr<views::View> CreateItemView() = 0;
 
+    // Called when the selected state of this item changes. Subclasses may
+    // assume that they are the only selected item in |list| when this is
+    // called.
+    virtual void SelectedStateChanged() = 0;
+
    private:
     std::unique_ptr<views::View> item_view_;
+    PaymentRequestItemList* list_;
+    bool selected_;
 
     DISALLOW_COPY_AND_ASSIGN(Item);
   };
@@ -47,7 +64,7 @@ class PaymentRequestItemList {
   PaymentRequestItemList();
   ~PaymentRequestItemList();
 
-  // Adds an item to this list.
+  // Adds an item to this list. |item->list()| should be equal to this object.
   void AddItem(std::unique_ptr<Item> item);
 
   // Creates and returns the UI representation of this list. It iterates over
@@ -55,6 +72,9 @@ class PaymentRequestItemList {
   // hierarchy.
   std::unique_ptr<views::View> CreateListView();
 
+  // Deselects the currently selected item and selects |item| instead.
+  void SelectItem(Item* item);
+
  private:
   std::vector<std::unique_ptr<Item>> items_;