Tab dragging as implemented as a mus API.

components/mus/demo/mus_demo.cc

Index: components/mus/demo/mus_demo.cc
diff --git a/components/mus/demo/mus_demo.cc b/components/mus/demo/mus_demo.cc
index 017e36c14b7982ee966df12a82b42e58f5d52eb1..5b7a143fe5a79de6f13994c3e2646d607607c0dc 100644
--- a/components/mus/demo/mus_demo.cc
+++ b/components/mus/demo/mus_demo.cc
@@ -128,6 +128,15 @@ void MusDemo::OnAccelerator(uint32_t id, const ui::Event& event) {
   // Don't care
 }
 
+void MusDemo::OnWmPerformMoveLoop(::mus::Window* window,
+                                  ::mus::mojom::MoveLoopSource source,
+                                  const gfx::Point& cursor_location,
+                                  const base::Callback<void(bool)>& on_done) {
+  // Don't care
+}
+
+void MusDemo::OnWmCancelMoveLoop(::mus::Window* window) {}
+
 void MusDemo::AllocBitmap() {
   const gfx::Rect bounds = window_->GetBoundsInRoot();