Tab dragging as implemented as a mus API.

services/ui/demo/mus_demo.cc

Index: services/ui/demo/mus_demo.cc
diff --git a/services/ui/demo/mus_demo.cc b/services/ui/demo/mus_demo.cc
index ecc313fd12ed72dee0332991b11482f9c0c6ae8e..ea9ff6062eb18e4639d42e8f9c7517647639f7d2 100644
--- a/services/ui/demo/mus_demo.cc
+++ b/services/ui/demo/mus_demo.cc
@@ -130,6 +130,15 @@ void MusDemo::OnAccelerator(uint32_t id, const ui::Event& event) {
   // Don't care
 }
 
+void MusDemo::OnWmPerformMoveLoop(ui::Window* window,
+                                  ui::mojom::MoveLoopSource source,
+                                  const gfx::Point& cursor_location,
+                                  const base::Callback<void(bool)>& on_done) {
+  // Don't care
+}
+
+void MusDemo::OnWmCancelMoveLoop(ui::Window* window) {}
+
 void MusDemo::AllocBitmap() {
   const gfx::Rect bounds = window_->GetBoundsInRoot();