Remove unused references to NativeTheme in TrayPopupItemStyle.

ash/common/system/chromeos/tray_tracing.cc

Index: ash/common/system/chromeos/tray_tracing.cc
diff --git a/ash/common/system/chromeos/tray_tracing.cc b/ash/common/system/chromeos/tray_tracing.cc
index 581149bfb54a534c27391e5573070087d7bd4843..43b1afb98d58dd8afb8e0ab7b82ae4a081aa82f4 100644
--- a/ash/common/system/chromeos/tray_tracing.cc
+++ b/ash/common/system/chromeos/tray_tracing.cc
@@ -41,13 +41,18 @@ class DefaultTracingView : public ActionableView {
     image_ = TrayPopupUtils::CreateMainImageView();
     tri_view->AddView(TriView::Container::START, image_);
 
-    label_ = TrayPopupUtils::CreateDefaultLabel();
-    label_->SetMultiLine(true);
-    label_->SetText(bundle.GetLocalizedString(IDS_ASH_STATUS_TRAY_TRACING));
-    tri_view->AddView(TriView::Container::CENTER, label_);
+    auto label = TrayPopupUtils::CreateDefaultLabel();
+    label->SetMultiLine(true);
+    label->SetText(bundle.GetLocalizedString(IDS_ASH_STATUS_TRAY_TRACING));
+    tri_view->AddView(TriView::Container::CENTER, label);
 
     if (MaterialDesignController::UseMaterialDesignSystemIcons()) {
-      UpdateStyle();
+      TrayPopupItemStyle style(
+          TrayPopupItemStyle::FontStyle::DEFAULT_VIEW_LABEL);
+      style.SetupLabel(label);
+      image_->SetImage(

[tdanderson, 2017/02/01 23:01:52]

I think |image_| can be made a non-member as well, similar to what you're doing
for the label.

[Evan Stade, 2017/02/02 22:49:53]

Done.

+          gfx::CreateVectorIcon(kSystemMenuTracingIcon, style.GetIconColor()));
+
       SetInkDropMode(InkDropHostView::InkDropMode::ON);
     } else {
       // The icon doesn't change in non-md.
@@ -59,24 +64,6 @@ class DefaultTracingView : public ActionableView {
   ~DefaultTracingView() override {}
 
  private:
-  // Update text and image color based on the current theme of the system.
-  void UpdateStyle() {
-    TrayPopupItemStyle style(GetNativeTheme(),
-                             TrayPopupItemStyle::FontStyle::DEFAULT_VIEW_LABEL);
-    style.SetupLabel(label_);
-    image_->SetImage(
-        gfx::CreateVectorIcon(kSystemMenuTracingIcon, style.GetIconColor()));
-  }
-
-  // ActionableView:
-  void OnNativeThemeChanged(const ui::NativeTheme* theme) override {
-    ActionableView::OnNativeThemeChanged(theme);
-
-    if (!MaterialDesignController::IsSystemTrayMenuMaterial())
-      return;
-    UpdateStyle();
-  }
-
   bool PerformAction(const ui::Event& event) override {
     WmShell::Get()->RecordUserMetricsAction(
         UMA_STATUS_AREA_TRACING_DEFAULT_SELECTED);
@@ -86,7 +73,6 @@ class DefaultTracingView : public ActionableView {
   }
 
   views::ImageView* image_;
-  views::Label* label_;
 
   DISALLOW_COPY_AND_ASSIGN(DefaultTracingView);
 };