Determine branch for which to show changesets via URL

scm-ui/src/changesets/components/DropDown.js

@@ -4,15 +4,17 @@ import React from "react";
 
 type Props = {
   options: string[],
-  optionSelected: string => void
+  optionSelected: string => void,
+  preselectedOption: string
 }
 
 class DropDown extends React.Component<Props> {
   render() {
-    const {options} = this.props;
-    return <select onChange={this.change}>
+    const {options, preselectedOption} = this.props;
+    return <select value={preselectedOption} onChange={this.change}>
       {options.map(option => {
-        return <option key={option} value={option}>{option}</option>
+        return <option key={option}
+                       value={option}>{option}</option>
       })}
     </select>
   }