diff --git a/experimental/sksg/SkSGInvalidationController.cpp b/experimental/sksg/SkSGInvalidationController.cpp
new file mode 100644
index 0000000..9693f1e
--- /dev/null
+++ b/experimental/sksg/SkSGInvalidationController.cpp
@@ -0,0 +1,20 @@
+/*
+ * Copyright 2017 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#include "SkSGInvalidationController.h"
+
+#include "SkRect.h"
+
+namespace sksg {
+
+InvalidationController::InvalidationController() {}
+
+void InvalidationController::inval(const SkRect& r) {
+    fRects.push(r);
+}
+
+} // namespace sksg