[Web Payments] Implement proper focusing in Payment Request

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

Index: chrome/browser/ui/views/payments/payment_request_row_view.cc
diff --git a/chrome/browser/ui/views/payments/payment_request_row_view.cc b/chrome/browser/ui/views/payments/payment_request_row_view.cc
index 05cdb38e999b986af13264bd56ce0a44a993ae1d..a613e77efa4a9e9c637355ede7f1cd4be62deadf 100644
--- a/chrome/browser/ui/views/payments/payment_request_row_view.cc
+++ b/chrome/browser/ui/views/payments/payment_request_row_view.cc
@@ -16,6 +16,7 @@ PaymentRequestRowView::PaymentRequestRowView(views::ButtonListener* listener,
     : views::CustomButton(listener), clickable_(clickable) {
   SetEnabled(clickable_);
   SetBorder(payments::CreatePaymentRequestRowBorder());
+  SetFocusBehavior(views::View::FocusBehavior::ALWAYS);
 }
 
 PaymentRequestRowView::~PaymentRequestRowView() {}
@@ -30,4 +31,18 @@ void PaymentRequestRowView::StateChanged(ButtonState old_state) {
   }
 }
 
+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