Explicitly set focus behavior of FocusableLabelButton

FocusableLabelButton already sets its own focus ring. It is meant to be
focusable as well. So explicitly set its focus behavior in this class
instead of setting it for each instance.

Bug: 1001103
Change-Id: Ie2169e9bf8a3d27200444c03da86f69eae6ee725
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2495702Reviewed-by: Denis Kuznetsov [CET] <antrim@chromium.org>
Commit-Queue: Wei Li <weili@chromium.org>
Cr-Commit-Position: refs/heads/master@{#820788}

ash/login/ui/pin_request_view.cc

@@ -100,6 +100,7 @@ class PinRequestView::FocusableLabelButton : public views::LabelButton {
       : views::LabelButton(listener, text) {
     SetInstallFocusRingOnFocus(true);
     focus_ring()->SetColor(ShelfConfig::Get()->shelf_focus_border_color());
+    SetFocusBehavior(FocusBehavior::ALWAYS);
   }
 
   FocusableLabelButton(const FocusableLabelButton&) = delete;
@@ -366,7 +367,6 @@ PinRequestView::PinRequestView(PinRequest request, Delegate* delegate)
   help_button_->layer()->SetFillsBoundsOpaquely(false);
   help_button_->SetTextSubpixelRenderingEnabled(false);
   help_button_->SetEnabledTextColors(kTextColor);
-  help_button_->SetFocusBehavior(FocusBehavior::ALWAYS);
   help_button_->SetVisible(request.help_button_enabled);
   footer->AddChildView(help_button_);