[ash-md] Updates ash shelf tooltips to MD

ash/common/material_design/material_design_controller.cc

Index: ash/common/material_design/material_design_controller.cc
diff --git a/ash/common/material_design/material_design_controller.cc b/ash/common/material_design/material_design_controller.cc
index 0c2bc5572188ef7979ef281885969a481116e46d..c353c783881381ba700ac68586d6d34b9cb87f7f 100644
--- a/ash/common/material_design/material_design_controller.cc
+++ b/ash/common/material_design/material_design_controller.cc
@@ -68,6 +68,11 @@ bool MaterialDesignController::IsShelfMaterial() {
 }
 
 // static
+bool MaterialDesignController::IsTooltipMaterial() {
+  return MaterialDesignController::IsMaterialExperimental();
+}
+
+// static
 bool MaterialDesignController::UseMaterialDesignSystemIcons() {
   return MaterialDesignController::IsMaterialExperimental();
 }