rebaseline_server: fix sorting by perceptual diff column

gm/rebaseline_server/static/loader.js

 /*
  * Loader:
  * Reads GM result reports written out by results.py, and imports
  * them into $scope.extraColumnHeaders and $scope.imagePairs .
  */
 var Loader = angular.module(
     'Loader',
     ['ConstantsModule']
 );
 
@@ skipping 84 matching lines @@
               function(){location.reload();},
               timeToReload - timeNow);
         } else {
           $scope.loadingMessage = "processing data, please wait...";
 
           $scope.header = dataHeader;
           $scope.extraColumnHeaders = data[constants.KEY__EXTRACOLUMNHEADERS];
           $scope.imagePairs = data[constants.KEY__IMAGEPAIRS];
           $scope.imageSets = data[constants.KEY__IMAGESETS];
           $scope.sortColumnSubdict = constants.KEY__DIFFERENCE_DATA;
-          $scope.sortColumnKey = constants.KEY__DIFFERENCE_DATA__WEIGHTED_DIFF;
+          $scope.sortColumnKey = constants.KEY__DIFFERENCE_DATA__PERCEPTUAL_DIFF;
 
           $scope.showSubmitAdvancedSettings = false;
           $scope.submitAdvancedSettings = {};
           $scope.submitAdvancedSettings[
               constants.KEY__EXPECTATIONS__REVIEWED] = true;
           $scope.submitAdvancedSettings[
               constants.KEY__EXPECTATIONS__IGNOREFAILURE] = false;
           $scope.submitAdvancedSettings['bug'] = '';
 
           // Create the list of tabs (lists into which the user can file each
@@ skipping 288 matching lines @@
       // array copies?  (For better performance.)
 
       if ($scope.viewingTab == $scope.defaultTab) {
 
         // TODO(epoger): Until we allow the user to reverse sort order,
         // there are certain columns we want to sort in a different order.
         var doReverse = (
             ($scope.sortColumnKey ==
              constants.KEY__DIFFERENCE_DATA__PERCENT_DIFF_PIXELS) ||
             ($scope.sortColumnKey ==
-             constants.KEY__DIFFERENCE_DATA__WEIGHTED_DIFF));
+             constants.KEY__DIFFERENCE_DATA__PERCEPTUAL_DIFF));
 
         $scope.filteredImagePairs =
             $filter("orderBy")(
                 $filter("removeHiddenImagePairs")(
                     $scope.imagePairs,
                     $scope.hiddenResultTypes,
                     $scope.hiddenConfigs,
                     $scope.categoryValueMatch.builder,
                     $scope.categoryValueMatch.test,
                     $scope.viewingTab
@@ skipping 378 matching lines @@
      */
     $scope.getImageDiffRelativeUrl = function(imagePair) {
       var before =
           imagePair[constants.KEY__IMAGE_A_URL] + "-vs-" +
           imagePair[constants.KEY__IMAGE_B_URL];
       return before.replace(/[^\w\-]/g, "_") + ".png";
     }
 
   }
 );