Implement all system menu title row buttons for Ash MD

ash/common/system/tray/tray_details_view.h

Index: ash/common/system/tray/tray_details_view.h
diff --git a/ash/common/system/tray/tray_details_view.h b/ash/common/system/tray/tray_details_view.h
index 976f780adeecc3288972fe6fb6634468e8f0f8f1..7736a90a44104a05368d097e37acf3423e9f0b11 100644
--- a/ash/common/system/tray/tray_details_view.h
+++ b/ash/common/system/tray/tray_details_view.h
@@ -76,9 +76,6 @@ class ASH_EXPORT TrayDetailsView : public views::View,
   // Creates and adds subclass-specific buttons to the title row.
   virtual void CreateExtraTitleRowButtons();
 
-  // Overridden to show WebUI settings for subclass-specific detailed views.
-  virtual void ShowSettings();
-
   // Transition to default view from details view. If |title_row_| has focus
   // before transition, the default view should focus on the owner of this
   // details view.
@@ -93,10 +90,6 @@ class ASH_EXPORT TrayDetailsView : public views::View,
   // The back button that appears in the material design title row. Not owned.
   views::Button* back_button_;
 
-  // The settings button that appears in the material design title row. Not
-  // owned.
-  views::Button* settings_button_;
-
   DISALLOW_COPY_AND_ASSIGN(TrayDetailsView);
 };