Ash Tray: Add some padding to the date info button so the focus ring is rendered better.

TEST=manually verified UI
BUG=860190

Change-Id: I431cf99e850f77ab64a02e054272c449cd9bc04e
Reviewed-on: https://chromium-review.googlesource.com/c/1490505
Commit-Queue: Tim Song <tengs@chromium.org>
Reviewed-by: Tetsui Ohkubo <tetsui@chromium.org>
Cr-Commit-Position: refs/heads/master@{#635916}

ash/system/tray/tray_constants.h

@@ -206,6 +206,7 @@ constexpr int kTrayTopShortcutButtonIconSize = 20;
 
 constexpr int kUnifiedSystemInfoHeight = 16;
 constexpr int kUnifiedSystemInfoSpacing = 8;
+constexpr gfx::Insets kUnifiedSystemInfoDateViewPadding(3);
 
 // Constants used in FeaturePodsView of UnifiedSystemTray.
 constexpr gfx::Size kUnifiedFeaturePodIconSize(48, 48);

ash/system/unified/unified_system_info_view.cc

@@ -63,6 +63,7 @@ class DateView : public views::Button,
   void Update();
 
   // views::Button:
+  gfx::Insets GetInsets() const override;
   std::unique_ptr<views::InkDrop> CreateInkDrop() override;
   std::unique_ptr<views::InkDropRipple> CreateInkDropRipple() const override;
   std::unique_ptr<views::InkDropHighlight> CreateInkDropHighlight()
@@ -116,6 +117,11 @@ void DateView::Update() {
   NotifyAccessibilityEvent(ax::mojom::Event::kTextChanged, true);
 }
 
+gfx::Insets DateView::GetInsets() const {
+  // This padding provides room to render the focus ring around this button.
+  return kUnifiedSystemInfoDateViewPadding;
+}
+
 std::unique_ptr<views::InkDrop> DateView::CreateInkDrop() {
   return TrayPopupUtils::CreateInkDrop(this);
 }