[Web Payments] Implement proper focusing in Payment Request

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

 // Copyright 2017 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CHROME_BROWSER_UI_VIEWS_PAYMENTS_PAYMENT_REQUEST_ROW_VIEW_H_
 #define CHROME_BROWSER_UI_VIEWS_PAYMENTS_PAYMENT_REQUEST_ROW_VIEW_H_
 
 #include "base/macros.h"
 #include "ui/views/controls/button/custom_button.h"
 
 namespace payments {
 
 // This class implements a clickable row of the Payment Request dialog that
 // darkens on hover and displays a horizontal ruler on its lower bound.
 class PaymentRequestRowView : public views::CustomButton {
  public:
   // Creates a row view. If |clickable| is true, the row will be shaded on hover
   // and handle click events.
   PaymentRequestRowView(views::ButtonListener* listener, bool clickable);
   ~PaymentRequestRowView() override;
 
+ private:
+  // Sets this row's background to the theme's hovered color to indicate that
+  // it's begin hovered or it's focused.
+  void SetActiveBackground();
+
   // views::CustomButton:
   void StateChanged(ButtonState old_state) override;
 
- private:
+  // views::View:
+  void OnFocus() override;
+  void OnBlur() override;
+
   bool clickable_;
 
   DISALLOW_COPY_AND_ASSIGN(PaymentRequestRowView);
 };
 
 }  // namespace payments
 
 #endif  // CHROME_BROWSER_UI_VIEWS_PAYMENTS_PAYMENT_REQUEST_ROW_VIEW_H_