Ignore setSelectionRange when node is un-parented.

LayoutTests/editing/input/orphan-set-selection-range.html

Index: LayoutTests/editing/input/orphan-set-selection-range.html
diff --git a/LayoutTests/editing/input/orphan-set-selection-range.html b/LayoutTests/editing/input/orphan-set-selection-range.html
new file mode 100644
index 0000000000000000000000000000000000000000..ff7dd10f639e44ec5ee967fdaaaa2ee8246e3e6d
--- /dev/null
+++ b/LayoutTests/editing/input/orphan-set-selection-range.html
@@ -0,0 +1,12 @@
+<script src="../../resources/js-test.js"></script>
+<script>
+  description = "Calling setSelectionRange() on an orphaned text node should be a no-op.";
+
+  div = document.createElement('div');
+  input = document.createElement('input');
+  div.appendChild(input);
+  input.setSelectionRange(0, 0);
+  doc = document.implementation.createDocument("", null);
+  doc.appendChild(div);
+  document.execCommand("FindString", false, "test");
+</script>