[reland] Makes MaterialDesignController initialization explicit

ui/base/test/material_design_controller_test_api.h

Index: ui/base/test/material_design_controller_test_api.h
diff --git a/ui/base/test/material_design_controller_test_api.h b/ui/base/test/material_design_controller_test_api.h
index 96aab7b01711aced9513c327722e2c57d58115a2..3eb53a349f5585ad03e677b5e84478335a66b271 100644
--- a/ui/base/test/material_design_controller_test_api.h
+++ b/ui/base/test/material_design_controller_test_api.h
@@ -12,17 +12,24 @@ namespace ui {
 namespace test {
 
 // Test API to access the internal state of the MaterialDesignController class.
+// Creating an instance of this class and then destroying it preserves global
+// state in MaterialDesignController class.
 class MaterialDesignControllerTestAPI {
  public:
+  explicit MaterialDesignControllerTestAPI(MaterialDesignController::Mode mode);
+  ~MaterialDesignControllerTestAPI();
+
   // Wrapper functions for MaterialDesignController internal functions.
-  static void SetMode(MaterialDesignController::Mode mode);
-  static void UninitializeMode();
+  static void Uninitialize();
 
  private:
+  const MaterialDesignController::Mode previous_mode_;
+  const bool previous_initialized_;
+
   DISALLOW_COPY_AND_ASSIGN(MaterialDesignControllerTestAPI);
 };
 
 }  // namespace test
 }  // namespace ui
 
-#endif  // UI_BASE_TEST_MATERIAL_DESIGN_CONTROLLER_TEST_AP_H_
+#endif  // UI_BASE_TEST_MATERIAL_DESIGN_CONTROLLER_TEST_API_H_