Update app menu button MD colors for the notification case.

chrome/browser/ui/views/toolbar/wrench_toolbar_button.h

Index: chrome/browser/ui/views/toolbar/wrench_toolbar_button.h
diff --git a/chrome/browser/ui/views/toolbar/wrench_toolbar_button.h b/chrome/browser/ui/views/toolbar/wrench_toolbar_button.h
index c8cf28e7686256852e0c727ff4963eeb28a4c198..49bd103e89df3e4f4169928a3c18eb8c7daf2799 100644
--- a/chrome/browser/ui/views/toolbar/wrench_toolbar_button.h
+++ b/chrome/browser/ui/views/toolbar/wrench_toolbar_button.h
@@ -56,6 +56,10 @@ class WrenchToolbarButton : public views::MenuButton,
   // WrenchIconPainter::Delegate:
   void ScheduleWrenchIconPaint() override;
 
+  // Updates the presentation according to |severity_| and the theme provider.
+  // Only used in MD.
+  void UpdateIcon();
+
   // Opens the app menu immediately during a drag-and-drop operation.
   // Used only in testing.
   static bool g_open_app_immediately_for_testing;
@@ -74,8 +78,12 @@ class WrenchToolbarButton : public views::MenuButton,
   int OnPerformDrop(const ui::DropTargetEvent& event) override;
   void OnPaint(gfx::Canvas* canvas) override;
 
+  // Only used in pre-MD.
   scoped_ptr<WrenchIconPainter> wrench_icon_painter_;
 
+  // Only used in MD.
+  WrenchIconPainter::Severity severity_;
+
   // Our owning toolbar view.
   ToolbarView* toolbar_view_;