Set Ash material design mode in tests properly

ash/test/ash_test_helper.h

Index: ash/test/ash_test_helper.h
diff --git a/ash/test/ash_test_helper.h b/ash/test/ash_test_helper.h
index 345d8273c5a2e11ba0bf2ed9d01b3d78dc9edc10..4c0978f2dd92b825dcf2fb891ca7a777af53352e 100644
--- a/ash/test/ash_test_helper.h
+++ b/ash/test/ash_test_helper.h
@@ -7,6 +7,8 @@
 
 #include <memory>
 
+#include "ash/common/material_design/material_design_controller.h"
+#include "ash/test/material_design_controller_test_api.h"
 #include "base/compiler_specific.h"
 #include "base/macros.h"
 
@@ -42,10 +44,12 @@ class AshTestHelper {
   explicit AshTestHelper(base::MessageLoopForUI* message_loop);
   ~AshTestHelper();
 
-  // Creates the ash::Shell and performs associated initialization.
-  // Set |start_session| to true if the user should log in before
-  // the test is run.
-  void SetUp(bool start_session);
+  // Creates the ash::Shell and performs associated initialization.  Set
+  // |start_session| to true if the user should log in before the test is run.
+  // |material_mode| determines the material design mode to be used for the
+  // tests. If |material_mode| is UNINITIALIZED, the value from command line
+  // switches is used.
+  void SetUp(bool start_session, MaterialDesignController::Mode material_mode);
 
   // Destroys the ash::Shell and performs associated cleanup.
   void TearDown();
@@ -107,6 +111,8 @@ class AshTestHelper {
   bool bluez_dbus_manager_initialized_;
 #endif
 
+  std::unique_ptr<test::MaterialDesignControllerTestAPI> material_design_state_;
+
   DISALLOW_COPY_AND_ASSIGN(AshTestHelper);
 };