Set focusibility correctly when initializing a window in mus+ash.

ash/mus/top_level_window_factory.cc

Index: ash/mus/top_level_window_factory.cc
diff --git a/ash/mus/top_level_window_factory.cc b/ash/mus/top_level_window_factory.cc
index f3260d0d3482cc0cd3c78df6bd64c6f1a7ac2f03..705bfc28c3c5941c79ff342f4d91bf114eadca89 100644
--- a/ash/mus/top_level_window_factory.cc
+++ b/ash/mus/top_level_window_factory.cc
@@ -21,6 +21,7 @@
 #include "services/ui/public/interfaces/window_manager_constants.mojom.h"
 #include "ui/aura/mus/property_converter.h"
 #include "ui/aura/mus/property_utils.h"
+#include "ui/aura/mus/window_tree_client.h"
 #include "ui/aura/window.h"
 #include "ui/display/display.h"
 
@@ -186,6 +187,12 @@ aura::Window* CreateAndParentTopLevelWindow(
     // No need to persist this value.

[sky, 2017/01/26 18:59:04]

Any properties left in properties are mirrored to the window-server. As
focusable is only useful at construction time you can remove it from properties
similar to what happens on this line.

[Hadi, 2017/01/26 20:23:17]

Done.

     properties->erase(ui::mojom::WindowManager::kWindowIgnoredByShelf_Property);
   }
+  if (properties->count(ui::mojom::WindowManager::kFocusable_InitProperty)) {
+    window_manager->window_tree_client()->SetCanFocus(
+        window,
+        mojo::ConvertTo<bool>(
+            (*properties)[ui::mojom::WindowManager::kFocusable_InitProperty]));
+  }
   return window;
 }