Tab dragging as implemented as a mus API.

ash/mus/window_manager.h

Index: ash/mus/window_manager.h
diff --git a/ash/mus/window_manager.h b/ash/mus/window_manager.h
index a922d52291fa3523b9e3c1041c509c474d475690..80537b43059ff41e1289738771e8bae88dce2c45 100644
--- a/ash/mus/window_manager.h
+++ b/ash/mus/window_manager.h
@@ -10,6 +10,7 @@
 #include <memory>
 #include <set>
 
+#include "ash/common/wm/wm_toplevel_window_event_handler.h"
 #include "base/macros.h"
 #include "base/observer_list.h"
 #include "components/mus/common/types.h"
@@ -66,6 +67,11 @@ class WindowManager : public ::mus::WindowManagerDelegate,
   ::mus::Window* NewTopLevelWindow(
       std::map<std::string, std::vector<uint8_t>>* properties);
 
+  // Called from WmMoveLoop to delete the object.
+  void OnWmMoveLoopCompleted(uint32_t change_id,
+                             uint32_t window_id,
+                             bool succeeded);
+
   std::set<RootWindowController*> GetRootWindowControllers();
 
   void AddRootWindowsObserver(RootWindowsObserver* observer);
@@ -104,6 +110,10 @@ class WindowManager : public ::mus::WindowManagerDelegate,
   void OnWmNewDisplay(::mus::Window* window,
                       const display::Display& display) override;
   void OnAccelerator(uint32_t id, const ui::Event& event) override;
+  void OnWmPerformMoveLoop(uint32_t change_id,
+                           uint32_t window_id,
+                           const gfx::Point& cursor_location) override;
+  void OnWmCancelMoveLoop(uint32_t window_id) override;
 
   // TODO(sky): this is unfortunate, remove.
   WindowManagerApplication* window_manager_app_;