aura-mus: add a drag representation image.

services/ui/ws/test_utils.h

Index: services/ui/ws/test_utils.h
diff --git a/services/ui/ws/test_utils.h b/services/ui/ws/test_utils.h
index 3f68927b607b55be389bc2c02f4aa0e74ba20454..8ab69ddbcfa9320057dcb712edab960c13719ec2 100644
--- a/services/ui/ws/test_utils.h
+++ b/services/ui/ws/test_utils.h
@@ -347,6 +347,13 @@ class TestWindowManager : public mojom::WindowManager {
       override;
   void WmClientJankinessChanged(ClientSpecificId client_id,
                                 bool janky) override;
+  void WmBuildDragImage(const gfx::Point& cursor_location,
+                        const SkBitmap& drag_image,
+                        const gfx::Vector2d& drag_image_offset,
+                        ui::mojom::DragEventSource source) override;
+  void WmMoveDragImage(const gfx::Point& cursor_location,
+                       const WmMoveDragImageCallback& callback) override;
+  void WmDestroyDragImage() override;
   void WmPerformMoveLoop(uint32_t change_id,
                          uint32_t window_id,
                          mojom::MoveLoopSource source,