Set Ash material design mode in tests properly

ash/shelf/shelf_view_unittest.cc

Index: ash/shelf/shelf_view_unittest.cc
diff --git a/ash/shelf/shelf_view_unittest.cc b/ash/shelf/shelf_view_unittest.cc
index b864b815be60d6cc31adac3473a4f9fa7de77b66..7df5f14402662d500183148928ad8fda285e9f62 100644
--- a/ash/shelf/shelf_view_unittest.cc
+++ b/ash/shelf/shelf_view_unittest.cc
@@ -2125,20 +2125,9 @@ class ShelfViewInkDropTest : public ShelfViewTest {
     shell_delegate_ = new TestAppListShellDelegate;
     ash_test_helper()->set_test_shell_delegate(shell_delegate_);
 
-    ShelfViewTest::SetUp();
-
-    // TODO(mohsen): Ideally, we would want to set material mode before calling
-    // ShelfViewTest::SetUp() so that everything is set up with the correct
-    // material mode. Currently, this is not possible as it expects material
-    // mode be UNINITIALIZED. (See https://crbug.com/620093)
-    ash_md_controller_.reset(new ash::test::MaterialDesignControllerTestAPI(
-        ash::MaterialDesignController::MATERIAL_EXPERIMENTAL));
-  }
+    set_material_mode(ash::MaterialDesignController::MATERIAL_EXPERIMENTAL);

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

Just a thought (not necessarily something to address in this CL): if there are
going to be lots of places where we will need to make calls like this, maybe we
could change MaterialDesignController to look something like:

Mode MDC::ModeForShelf() {
  return EXPERIMENTAL;  // (*)
}

bool MDC::IsShelfMaterial() {
  return mode() == ModeForShelf();
}

then line 2128 could be:

set_material_mode(MDC::ModeForShelf());

The advantage is that when the MD shelf needs to change mode (e.g., if we
promote from EXPERIMENTAL to NORMAL) then (*) would be the only line that needs
to change.

[bruthig, 2016/07/29 16:13:04]

+1 to something like this. Could "ModeForShelf()" be replaced with a constant?

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

As discussed in person, this is not simple since EXPERIMENTAL also implies
NORMAL. For example, when shelf is promoted to NORMAL, then IsShelfMaterial()
should return true not just for NORMAL but also for EXPERIMENTAL. Maybe we need
to add some sort of ordering between modes. Anyways, better to address in
anotehr CL.

 
-  void TearDown() override {
-    ash_md_controller_.reset();
-
-    ShelfViewTest::TearDown();
+    ShelfViewTest::SetUp();
   }
 
  protected:
@@ -2179,9 +2168,6 @@ class ShelfViewInkDropTest : public ShelfViewTest {
     shell_delegate_->app_list_presenter()->FinishVisibilityChange();
   }
 
-  std::unique_ptr<ash::test::MaterialDesignControllerTestAPI>
-      ash_md_controller_;
-
   TestAppListShellDelegate* shell_delegate_ = nullptr;  // Owned by Shell.
 
   AppListButton* app_list_button_ = nullptr;