mus: Implement interwindow drag and drop

services/ui/ws/window_tree_client_unittest.cc

Index: services/ui/ws/window_tree_client_unittest.cc
diff --git a/services/ui/ws/window_tree_client_unittest.cc b/services/ui/ws/window_tree_client_unittest.cc
index 2931798f6eb33962f4c047364561c749b4df74f3..ad40b5baad5819be11b6bf5ae124d6e0fba5ca4c 100644
--- a/services/ui/ws/window_tree_client_unittest.cc
+++ b/services/ui/ws/window_tree_client_unittest.cc
@@ -371,6 +371,29 @@ class TestWindowTreeClient : public mojom::WindowTreeClient,
                                        mojom::Cursor cursor_id) override {
     tracker_.OnWindowPredefinedCursorChanged(window_id, cursor_id);
   }
+  void OnDragEnter(uint32_t window,
+                   mojo::Map<mojo::String, mojo::Array<uint8_t>> drag_data,
+                   uint32_t key_state,
+                   const gfx::Point& position,
+                   uint32_t effect_bitmask,
+                   const OnDragEnterCallback& callback) override {
+    NOTIMPLEMENTED();
+  }
+  void OnDragOver(uint32_t window,
+                  uint32_t key_state,
+                  const gfx::Point& position,
+                  uint32_t effect_bitmask,
+                  const OnDragOverCallback& callback) override {
+    NOTIMPLEMENTED();
+  }
+  void OnDragLeave(uint32_t window) override { NOTIMPLEMENTED(); }
+  void OnDragDrop(uint32_t window,
+                  uint32_t key_state,
+                  const gfx::Point& position,
+                  uint32_t effect_bitmask,
+                  const OnDragDropCallback& callback) override {
+    NOTIMPLEMENTED();
+  }
   void OnChangeCompleted(uint32_t change_id, bool success) override {
     if (waiting_change_id_ == change_id && change_completed_run_loop_) {
       on_change_completed_result_ = success;