Cleanup ash shelf accessor functions.

ash/shelf/shelf.h

Index: ash/shelf/shelf.h
diff --git a/ash/shelf/shelf.h b/ash/shelf/shelf.h
index 59cb0099ed30c6b1940734042f17fdf1e162b3de..62042ff2bf01b7937ee5a730e593769e389fe665 100644
--- a/ash/shelf/shelf.h
+++ b/ash/shelf/shelf.h
@@ -8,6 +8,7 @@
 #include "ash/ash_export.h"
 #include "ash/shelf/shelf_constants.h"
 #include "ash/shelf/shelf_types.h"
+#include "ash/shelf/shelf_widget.h"
 #include "base/macros.h"
 #include "base/memory/scoped_ptr.h"
 #include "ui/gfx/geometry/size.h"
@@ -35,13 +36,11 @@ class ShelfDelegate;
 class ShelfIconObserver;
 class ShelfModel;
 class ShelfView;
-class ShelfWidget;
 
 namespace test {
 class ShelfTestAPI;
 }
 
-
 class ASH_EXPORT Shelf {
  public:
   static const char kNativeViewName[];
@@ -53,9 +52,9 @@ class ASH_EXPORT Shelf {
   static Shelf* ForPrimaryDisplay();
 
   // Return the shelf for the display that |window| is currently on, or a shelf
-  // on primary display if the shelf per display feature  is disabled. NULL if
-  // no user is logged in yet.
-  static Shelf* ForWindow(aura::Window* window);
+  // on primary display if the shelf per display feature is disabled. NULL if no
+  // user is logged in yet.
+  static Shelf* ForWindow(const aura::Window* window);
 
   void SetAlignment(ShelfAlignment alignment);
   ShelfAlignment alignment() const { return alignment_; }
@@ -95,6 +94,9 @@ class ASH_EXPORT Shelf {
   void LaunchAppIndexAt(int item_index);
 
   ShelfWidget* shelf_widget() { return shelf_widget_; }
+  ShelfLayoutManager* shelf_layout_manager() {

[sky, 2016/02/29 16:38:39]

Seems unfortunate that we expose the ShelfLayoutManager at all. Seems like Shelf
should expose the api and call through to the necessary places.

[msw, 2016/02/29 23:23:44]

Agreed; I tackled some low-hanging fruit and added a TODO here. It'll take many
more followup changes to totally encapsulate ShelfLayoutManager.

+    return shelf_widget_->shelf_layout_manager();
+  }
 
   // Set the bounds of the shelf view.
   void SetShelfViewBounds(gfx::Rect bounds);