Refactors DockedWindowLayoutManager in terms of ash/wm/common

ash/shelf/shelf_util.cc

Index: ash/shelf/shelf_util.cc
diff --git a/ash/shelf/shelf_util.cc b/ash/shelf/shelf_util.cc
index b87d66800fd03de38ba77bd94e3e11b3e0ed9118..41c50007fe180168941b1b840bd68e95187ea039 100644
--- a/ash/shelf/shelf_util.cc
+++ b/ash/shelf/shelf_util.cc
@@ -58,9 +58,9 @@ const ShelfItemDetails* GetShelfItemDetailsForWindow(
   return window->GetProperty(kShelfItemDetailsKey);
 }
 
-bool IsHorizontalAlignment(ShelfAlignment alignment) {
-  return alignment == SHELF_ALIGNMENT_BOTTOM ||
-         alignment == SHELF_ALIGNMENT_BOTTOM_LOCKED;
+bool IsHorizontalAlignment(wm::ShelfAlignment alignment) {
+  return alignment == wm::SHELF_ALIGNMENT_BOTTOM ||
+         alignment == wm::SHELF_ALIGNMENT_BOTTOM_LOCKED;
 }
 
 }  // namespace ash