Move yet more from WmShell to Shell

ash/test/shell_test_api.h

Index: ash/test/shell_test_api.h
diff --git a/ash/test/shell_test_api.h b/ash/test/shell_test_api.h
index f1eb5d4c900cbb053d310fc6c8a17ea55c9457e7..0d1364c697c13e0eefebb4788f48463cb943e010 100644
--- a/ash/test/shell_test_api.h
+++ b/ash/test/shell_test_api.h
@@ -16,6 +16,7 @@ class MaximizeModeWindowManager;
 class PaletteDelegate;
 class SessionStateDelegate;
 class ScreenPositionController;
+class ShelfDelegate;
 class Shell;
 class SystemGestureEventFilter;
 class WorkspaceController;
@@ -37,6 +38,7 @@ class ShellTestApi {
 
   void SetPaletteDelegate(std::unique_ptr<PaletteDelegate> palette_delegate);
   void SetSessionStateDelegate(SessionStateDelegate* session_state_delegate);
+  void SetShelfDelegate(std::unique_ptr<ShelfDelegate> test_delegate);
 
  private:
   Shell* shell_;  // not owned