ash: Move more code from Shelf to WmShelf

ash/common/shelf/wm_shelf.h

Index: ash/common/shelf/wm_shelf.h
diff --git a/ash/common/shelf/wm_shelf.h b/ash/common/shelf/wm_shelf.h
index 33f4450941b68fdb525cd4cee2329bfb93771373..3172c0bfe00750fe36521e64384c137d670439a6 100644
--- a/ash/common/shelf/wm_shelf.h
+++ b/ash/common/shelf/wm_shelf.h
@@ -36,6 +36,10 @@ class WmWindow;
 // controller. Note that the shelf widget may not be created until after login.
 class ASH_EXPORT WmShelf : public ShelfLayoutManagerObserver {
  public:
+  // Returns the shelf for the display that |window| is on. Note that the shelf
+  // widget may not exist, or the shelf may not be visible.
+  static WmShelf* ForWindow(WmWindow* window);
+
   void SetShelf(Shelf* shelf);
   void ClearShelf();
   Shelf* shelf() const { return shelf_; }
@@ -99,12 +103,21 @@ class ASH_EXPORT WmShelf : public ShelfLayoutManagerObserver {
 
   gfx::Rect GetUserWorkAreaBounds() const;
 
-  void UpdateIconPositionForWindow(WmWindow* window);
+  // Updates the icon position given the current window bounds. This is used
+  // when dragging panels to reposition them with respect to the other panels.
+  void UpdateIconPositionForPanel(WmWindow* window);
 
   // Returns the screen bounds of the item for the specified window. If there is
   // no item for the specified window an empty rect is returned.
   gfx::Rect GetScreenBoundsOfItemIconForWindow(WmWindow* window);
 
+  // Launch a 0-indexed shelf item in the shelf. A negative index launches the
+  // last shelf item in the shelf.
+  static void LaunchAppAtIndex(int item_index);

[msw, 2016/08/25 00:22:24]

nit: converge on (*AppAtIndex or *ShelfItem) and (|index| or |item_index|)

[James Cook, 2016/08/25 02:29:13]

Done.

+
+  // Activates the shelf item specified by the index in the list of shelf items.
+  static void ActivateShelfItem(int index);
+
   // Handles a gesture |event| coming from a source outside the shelf widget
   // (e.g. the status area widget). Allows support for behaviors like toggling
   // auto-hide with a swipe, even if that gesture event hits another window.