Fix scrolling issues of iFrame.

layouts/scripts/toolbar/data-options/DataOptions.jsx

@@ -98,7 +98,12 @@ function DataOptions(props = {}) {
 
   async function changeDataOption(e) {
     const dataName = e.target.value;
-    props.rootAttributes.previewFrame.src = window.devTool.previewFrameUrl + '?data=' + dataName;
+
+    const previewFrameUrl = new URL(window.devTool.previewFrameUrl);
+    previewFrameUrl.searchParams.set('data', dataName);
+    previewFrameUrl.searchParams.set('iframe', 'true');
+
+    props.rootAttributes.previewFrame.src = previewFrameUrl.href;
 
     const dataOption = await fetchDataOptions(dataName);
     updateState(Object.assign({}, dataOption, {dataName}));