rebaseline_server: tiny fix to un-break UI when ng-repeate (key, value) has duplicate values

See https://github.com/angular/angular.js/pull/2505

(SkipBuildbotRuns)
TBR=jcgregorio

Review URL: https://codereview.chromium.org/46063005

git-svn-id: http://skia.googlecode.com/svn/trunk@11972 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/gm/rebaseline_server/static/view.html b/gm/rebaseline_server/static/view.html
index 36da9ee..818d7de 100644
--- a/gm/rebaseline_server/static/view.html
+++ b/gm/rebaseline_server/static/view.html
@@ -91,7 +91,7 @@
       <!-- TODO(epoger): make this an ng-repeat over resultType, config, etc? -->
       <td>
         resultType<br>
-        <label ng-repeat="(resultType, count) in categories['resultType']">
+        <label ng-repeat="(resultType, count) in categories['resultType'] track by $index">
           <input type="checkbox"
                  name="resultTypes"
                  value="{{resultType}}"
@@ -102,7 +102,7 @@
       </td>
       <td>
         config<br>
-        <label ng-repeat="(config, count) in categories['config']">
+        <label ng-repeat="(config, count) in categories['config'] track by $index">
           <input type="checkbox"
                  name="configs"
                  value="{{config}}"