Converts ash/wm/mru_window_tracker_unittest.cc to use AshTest

ash/mus/property_util.h

Index: ash/mus/property_util.h
diff --git a/ash/mus/property_util.h b/ash/mus/property_util.h
index a0ede0188ae480c7d118266e94c1f36897b9dd73..1e9a0a89f035c5b483457ea200e4b4014ffaa395 100644
--- a/ash/mus/property_util.h
+++ b/ash/mus/property_util.h
@@ -88,6 +88,12 @@ bool ShouldRenderParentTitleArea(ui::Window* window);
 // kInvalidDisplayID.
 int64_t GetInitialDisplayId(const ui::Window::SharedProperties& properties);
 
+// Manipulates the kExcludeFromMru_Property property.

[msw, 2016/10/11 22:36:05]

optional nit: combine comments, remove blank line between.

[sky, 2016/10/11 22:57:05]

I like keeping separate as that way the comments are more focused.

+void SetExcludeFromMru(ui::Window* window, bool value);

[msw, 2016/10/11 22:36:05]

aside: it'd be nice if these were in a window_properties namespace or similar.

[sky, 2016/10/11 22:57:05]

How come? Generally we don't use namespaces based on files, but we've definitely
waffled on that.

+
+// Returns true if the property is set and true, otherwise false.
+bool GetExcludeFromMru(const ui::Window* window);

[msw, 2016/10/11 22:36:05]

very optional nit: IsExcludedFromMru? (like Is* bool getters above).

[sky, 2016/10/11 22:57:05]

I went with this to match the name of the property (both mus and ash one).

+
 }  // namespace mus
 }  // namespace ash