Added a comment

Signed-off-by: Šimon Brandner <simon.bra.ag@gmail.com>

src/components/views/elements/ImageView.js

@@ -53,6 +53,8 @@ export default class ImageView extends React.Component {
     }
 
     componentDidMount() {
+        // We have to use addEventListener() because the listener
+        // needs to be passive in order to work with Chromium
         this.focusLock.addEventListener('wheel', this.onWheel, { passive: false });
     }