Materialized the font/icon color for some default rows in the system menu.

ash/common/system/update/tray_update.cc

Index: ash/common/system/update/tray_update.cc
diff --git a/ash/common/system/update/tray_update.cc b/ash/common/system/update/tray_update.cc
index 42666496ef8770a2b5c9f059fe9c1d75a6ced018..15a0f48b6aaefc8a40fd0a728653d536edd51439 100644
--- a/ash/common/system/update/tray_update.cc
+++ b/ash/common/system/update/tray_update.cc
@@ -11,6 +11,7 @@
 #include "ash/common/system/tray/system_tray_delegate.h"
 #include "ash/common/system/tray/system_tray_notifier.h"
 #include "ash/common/system/tray/tray_constants.h"
+#include "ash/common/system/tray/tray_popup_item_style.h"
 #include "ash/common/wm_shell.h"
 #include "ash/resources/vector_icons/vector_icons.h"
 #include "grit/ash_resources.h"
@@ -80,7 +81,7 @@ SkColor IconColorForUpdateSeverity(UpdateInfo::UpdateSeverity severity,
 
 class UpdateView : public ActionableView {
  public:
-  explicit UpdateView(const UpdateInfo& info) {
+  explicit UpdateView(const UpdateInfo& info) : label_(nullptr) {
     SetLayoutManager(new views::BoxLayout(views::BoxLayout::kHorizontal,
                                           kTrayPopupPaddingHorizontal, 0,
                                           kTrayPopupPaddingBetweenItems));
@@ -98,13 +99,14 @@ class UpdateView : public ActionableView {
     }
     AddChildView(image);
 
-    base::string16 label =
+    base::string16 label_text =
         info.factory_reset_required
             ? bundle.GetLocalizedString(
                   IDS_ASH_STATUS_TRAY_RESTART_AND_POWERWASH_TO_UPDATE)
             : bundle.GetLocalizedString(IDS_ASH_STATUS_TRAY_UPDATE);
-    AddChildView(new views::Label(label));
-    SetAccessibleName(label);
+    label_ = new views::Label(label_text);
+    AddChildView(label_);
+    SetAccessibleName(label_text);
   }
 
   ~UpdateView() override {}
@@ -118,6 +120,19 @@ class UpdateView : public ActionableView {
     return true;
   }
 
+  void OnNativeThemeChanged(const ui::NativeTheme* theme) override {
+    ActionableView::OnNativeThemeChanged(theme);
+
+    if (!MaterialDesignController::IsSystemTrayMenuMaterial())
+      return;
+
+    TrayPopupItemStyle style(GetNativeTheme(),
+                             TrayPopupItemStyle::FontStyle::DEFAULT_VIEW_LABEL);
+    style.SetupLabel(label_);
+  }
+
+  views::Label* label_;
+
   DISALLOW_COPY_AND_ASSIGN(UpdateView);
 };