[Web Payments] Implement proper focusing in Payment Request

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

 // 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.
 
 #include "chrome/browser/ui/views/payments/payment_request_row_view.h"
 
 #include "chrome/browser/ui/views/payments/payment_request_views_util.h"
 #include "third_party/skia/include/core/SkColor.h"
 #include "ui/views/background.h"
 #include "ui/views/border.h"
 
 namespace payments {
 
 PaymentRequestRowView::PaymentRequestRowView(views::ButtonListener* listener,
                                              bool clickable)
     : views::CustomButton(listener), clickable_(clickable) {
   SetEnabled(clickable_);
   SetBorder(payments::CreatePaymentRequestRowBorder());
+  SetFocusBehavior(views::View::FocusBehavior::ALWAYS);
 }
 
 PaymentRequestRowView::~PaymentRequestRowView() {}
 
 // views::CustomButton:
 void PaymentRequestRowView::StateChanged(ButtonState old_state) {
   if (clickable_ && (state() == views::Button::STATE_HOVERED ||
                      state() == views::Button::STATE_PRESSED)) {
     set_background(views::Background::CreateSolidBackground(SK_ColorLTGRAY));
   } else {
     set_background(nullptr);
   }
 }
 
+void PaymentRequestRowView::OnFocus() {
+  if (clickable_) {
+    set_background(views::Background::CreateSolidBackground(SK_ColorLTGRAY));

[Mathieu, 2017/05/02 13:16:10]

We should get the proper color from the theme to use here and above, since it's
good for accessibility (e.g. high contrast mode)

https://cs.chromium.org/chromium/src/ui/native_theme/native_theme.h?rcl=eb669...

I'm thinking HoveredBackground ?

[anthonyvd, 2017/05/02 13:43:32]

Oh good call! Done.

+    SchedulePaint();
+  }
+}
+
+void PaymentRequestRowView::OnBlur() {
+  if (clickable_) {
+    set_background(nullptr);
+    SchedulePaint();
+  }
+}
+
 }  // namespace payments