rebaseline_server: add pixel diffs, and sorting by diff metrics

gm/rebaseline_server/static/loader.js

 /*
  * Loader:
  * Reads GM result reports written out by results.py, and imports
  * them into $scope.categories and $scope.testData .
  */
 var Loader = angular.module(
     'Loader',
     []
 );
 
@@ skipping 40 matching lines @@
      * Once the dictionary is loaded, unhide the page elements so they can
      * render the data.
      */
     $http.get("/results/" + resultsToLoad).success(
       function(data, status, header, config) {
         $scope.loadingMessage = "Processing data, please wait...";
 
         $scope.header = data.header;
         $scope.categories = data.categories;
         $scope.testData = data.testData;
-        $scope.sortColumn = 'test';
+        $scope.sortColumn = 'weightedDiffMeasure';
         $scope.showTodos = false;
 
         $scope.showSubmitAdvancedSettings = false;
         $scope.submitAdvancedSettings = {};
         $scope.submitAdvancedSettings['reviewed-by-human'] = true;
         $scope.submitAdvancedSettings['ignore-failure'] = false;
         $scope.submitAdvancedSettings['bug'] = '';
 
         // Create the list of tabs (lists into which the user can file each
         // test).  This may vary, depending on isEditable.
@@ skipping 163 matching lines @@
      * Update the displayed results, based on filters/settings.
      */
     $scope.updateResults = function() {
       $scope.displayLimit = $scope.displayLimitPending;
       // TODO(epoger): Every time we apply a filter, AngularJS creates
       // another copy of the array.  Is there a way we can filter out
       // the items as they are displayed, rather than storing multiple
       // 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.sortColumn == 'percentDifferingPixels') ||
+            ($scope.sortColumn == 'weightedDiffMeasure'));
+
         $scope.filteredTestData =
             $filter("orderBy")(
                 $filter("removeHiddenItems")(
                     $scope.testData,
                     $scope.hiddenResultTypes,
                     $scope.hiddenConfigs,
                     $scope.categoryValueMatch.builder,
                     $scope.categoryValueMatch.test,
                     $scope.viewingTab
                 ),
-                $scope.sortColumn);
+                $scope.sortColumn, doReverse);
         $scope.limitedTestData = $filter("limitTo")(
             $scope.filteredTestData, $scope.displayLimit);
       } else {
         $scope.filteredTestData =
             $filter("orderBy")(
                 $filter("filter")(
                     $scope.testData,
                     {tab: $scope.viewingTab},
                     true
                 ),
@@ skipping 235 matching lines @@
      *
      * @param secondsPastEpoch (numeric): seconds past epoch in UTC
      */
     $scope.localTimeString = function(secondsPastEpoch) {
       var d = new Date(secondsPastEpoch * 1000);
       return d.toString();
     }
 
   }
 );