mus: Let clients set the cursor of their window.

components/mus/public/cpp/lib/window.cc

Index: components/mus/public/cpp/lib/window.cc
diff --git a/components/mus/public/cpp/lib/window.cc b/components/mus/public/cpp/lib/window.cc
index 8dffc7f52d010f64002e31389124d3b7af0c2530..33649aeca1388458823af1ded26e9e71b9e588f7 100644
--- a/components/mus/public/cpp/lib/window.cc
+++ b/components/mus/public/cpp/lib/window.cc
@@ -210,6 +210,15 @@ void Window::SetVisible(bool value) {
   LocalSetVisible(value);
 }
 
+void Window::SetPredefinedCursor(mus::mojom::Cursor cursor_id) {
+  if (cursor_id_ == cursor_id)
+    return;
+
+  if (connection_)
+    tree_client()->SetPredefinedCursor(id_, cursor_id);
+  LocalSetPredefinedCursor(cursor_id);
+}
+
 bool Window::IsDrawn() const {
   if (!visible_)
     return false;
@@ -604,6 +613,15 @@ void Window::LocalSetVisible(bool visible) {
   NotifyWindowVisibilityChanged(this);
 }
 
+void Window::LocalSetPredefinedCursor(mojom::Cursor cursor_id) {
+  if (cursor_id_ == cursor_id)
+    return;
+
+  cursor_id_ = cursor_id;
+  FOR_EACH_OBSERVER(WindowObserver, observers_,
+                    OnWindowSetPredefinedCursor(this, cursor_id));
+}
+
 void Window::LocalSetSharedProperty(const std::string& name,
                                     const std::vector<uint8_t>* value) {
   std::vector<uint8_t> old_value;