[view history/snapshot/trash file] rewrote them with react

frontend/src/components/file-content-view/pdf.js

@@ -0,0 +1,16 @@
+import React from 'react';
+import PDFViewer from '../pdf-viewer';
+
+import '../../css/pdf-file-view.css';
+
+class FileContent extends React.Component {
+  render() {
+    return (
+      <div className="file-view-content flex-1 pdf-file-view">
+        <PDFViewer />
+      </div>
+    );
+  }
+}
+
+export default FileContent;