[top-chrome-md] Allows UpdateMaterialDesignColors to be called before MDC::Initialize()

ui/base/material_design/material_design_controller.h

Index: ui/base/material_design/material_design_controller.h
diff --git a/ui/base/material_design/material_design_controller.h b/ui/base/material_design/material_design_controller.h
index 46363f776b1a3622726865439f3f60def1e5db5c..65f4ab104135b0dac3924cddb07a00d740d5db2f 100644
--- a/ui/base/material_design/material_design_controller.h
+++ b/ui/base/material_design/material_design_controller.h
@@ -44,6 +44,8 @@ class UI_BASE_EXPORT MaterialDesignController {
   // Returns the per-platform default material design variant.
   static Mode DefaultMode();
 
+  static bool is_mode_initialized() { return is_mode_initialized_; }
+
  private:
   friend class test::MaterialDesignControllerTestAPI;