Support additional mash shelf alignments.

mash/wm/shelf_layout.h

Index: mash/wm/shelf_layout.h
diff --git a/mash/wm/shelf_layout.h b/mash/wm/shelf_layout.h
index 44f318230363cbb2e38ded63e2d2068952dffe66..4591f8e2be4455e3bc8ba75c7432ea98bb31985d 100644
--- a/mash/wm/shelf_layout.h
+++ b/mash/wm/shelf_layout.h
@@ -7,12 +7,14 @@
 
 #include "base/macros.h"
 #include "mash/wm/layout_manager.h"
+#include "mash/wm/public/interfaces/shelf_layout.mojom.h"
 
 namespace mash {
 namespace wm {
 
 // Lays out the shelf within shelf containers.
-class ShelfLayout : public LayoutManager {
+class ShelfLayout : public LayoutManager,
+                    public mojom::ShelfLayout {
  public:
   explicit ShelfLayout(mus::Window* owner);
   ~ShelfLayout() override;
@@ -21,6 +23,13 @@ class ShelfLayout : public LayoutManager {
   // Overridden from LayoutManager:
   void LayoutWindow(mus::Window* window) override;
 
+  // Overridden from mojom::ShelfLayout:
+  void SetAlignment(mojom::ShelfAlignment alignment) override;
+  void SetAutoHideBehavior(mojom::ShelfAutoHideBehavior auto_hide) override;
+
+  mojom::ShelfAlignment alignment_;
+  mojom::ShelfAutoHideBehavior auto_hide_;
+
   DISALLOW_COPY_AND_ASSIGN(ShelfLayout);
 };