Set Ash material design mode in tests properly

ash/test/ash_test_helper.cc

Index: ash/test/ash_test_helper.cc
diff --git a/ash/test/ash_test_helper.cc b/ash/test/ash_test_helper.cc
index dcc98bcae89c811fe64c64145c3f088583714a83..53ce9edd0f2731e053eaf58e9eb4640259c61a01 100644
--- a/ash/test/ash_test_helper.cc
+++ b/ash/test/ash_test_helper.cc
@@ -7,8 +7,6 @@
 #include "ash/accelerators/accelerator_controller_delegate_aura.h"
 #include "ash/common/ash_switches.h"
 #include "ash/common/display/display_info.h"
-#include "ash/common/material_design/material_design_controller.h"
-#include "ash/common/test/material_design_controller_test_api.h"
 #include "ash/common/wm_shell.h"
 #include "ash/shell.h"
 #include "ash/shell_init_params.h"
@@ -71,7 +69,8 @@ AshTestHelper::AshTestHelper(base::MessageLoopForUI* message_loop)
 
 AshTestHelper::~AshTestHelper() {}
 
-void AshTestHelper::SetUp(bool start_session) {
+void AshTestHelper::SetUp(bool start_session,
+                          MaterialDesignController::Mode material_mode) {
   ResetDisplayIdForTest();
   views_delegate_.reset(new AshTestViewsDelegate);
 
@@ -127,6 +126,12 @@ void AshTestHelper::SetUp(bool start_session) {
   ui::test::MaterialDesignControllerTestAPI::Uninitialize();
   ui::MaterialDesignController::Initialize();
   ash::MaterialDesignController::Initialize();
+  // If |material_mode| is not set, use the value from command line switches.

[tdanderson, 2016/07/29 15:16:50]

I think it would be better to have this documented in the .h above
AshTestHelper::SetUp() instead of buried in the implementation. Maybe also
explicitly call out the fact that if the |material_mode| parameter is something
other than UNINITIALIZED, any command line value will be ignored.

[mohsen, 2016/07/29 18:05:19]

Right. Done.

+  if (material_mode == MaterialDesignController::Mode::UNINITIALIZED)
+    material_mode = MaterialDesignController::GetMode();
+  material_design_state_.reset(
+      new test::MaterialDesignControllerTestAPI(material_mode));
+
   ShellInitParams init_params;
   init_params.delegate = test_shell_delegate_;
   init_params.context_factory = context_factory;
@@ -152,6 +157,7 @@ void AshTestHelper::SetUp(bool start_session) {
 void AshTestHelper::TearDown() {
   // Tear down the shell.
   Shell::DeleteInstance();
+  material_design_state_.reset();
   test::MaterialDesignControllerTestAPI::Uninitialize();
   ShellContentState::DestroyInstance();