don't list out all sourceSkpFile names in the rebaseline_server UI

(the list is long and crowds out the results themselves; better to use
a text filter to select the sourceSkpFiles of interest)

R=stephana@google.com
TBR=stephana
NOTREECHECKS=true
NOTRY=true

Author: epoger@google.com

Review URL: https://codereview.chromium.org/451853002
diff --git a/gm/rebaseline_server/compare_rendered_pictures.py b/gm/rebaseline_server/compare_rendered_pictures.py
index f472be2..1207979 100755
--- a/gm/rebaseline_server/compare_rendered_pictures.py
+++ b/gm/rebaseline_server/compare_rendered_pictures.py
@@ -46,6 +46,7 @@
 COLUMN__TILED_OR_WHOLE = 'tiledOrWhole'
 COLUMN__TILENUM = 'tilenum'
 FREEFORM_COLUMN_IDS = [
+    COLUMN__SOURCE_SKP,
     COLUMN__TILENUM,
 ]
 ORDERED_COLUMN_IDS = [
diff --git a/gm/rebaseline_server/testdata/outputs/expected/compare_rendered_pictures_test.CompareRenderedPicturesTest.test_endToEnd/compare_rendered_pictures.json b/gm/rebaseline_server/testdata/outputs/expected/compare_rendered_pictures_test.CompareRenderedPicturesTest.test_endToEnd/compare_rendered_pictures.json
index 03c5b29..4eb963b 100644
--- a/gm/rebaseline_server/testdata/outputs/expected/compare_rendered_pictures_test.CompareRenderedPicturesTest.test_endToEnd/compare_rendered_pictures.json
+++ b/gm/rebaseline_server/testdata/outputs/expected/compare_rendered_pictures_test.CompareRenderedPicturesTest.test_endToEnd/compare_rendered_pictures.json
@@ -24,7 +24,7 @@
       "headerText": "sourceSkpFile", 
       "isFilterable": true, 
       "isSortable": true, 
-      "useFreeformFilter": false, 
+      "useFreeformFilter": true, 
       "valuesAndCounts": [
         [
           "changed.skp", 
diff --git a/gm/rebaseline_server/testdata/outputs/expected/compare_rendered_pictures_test.CompareRenderedPicturesTest.test_repo_url/compare_rendered_pictures.json b/gm/rebaseline_server/testdata/outputs/expected/compare_rendered_pictures_test.CompareRenderedPicturesTest.test_repo_url/compare_rendered_pictures.json
index 4a817d3..8cfdbe6 100644
--- a/gm/rebaseline_server/testdata/outputs/expected/compare_rendered_pictures_test.CompareRenderedPicturesTest.test_repo_url/compare_rendered_pictures.json
+++ b/gm/rebaseline_server/testdata/outputs/expected/compare_rendered_pictures_test.CompareRenderedPicturesTest.test_repo_url/compare_rendered_pictures.json
@@ -24,7 +24,7 @@
       "headerText": "sourceSkpFile", 
       "isFilterable": true, 
       "isSortable": true, 
-      "useFreeformFilter": false, 
+      "useFreeformFilter": true, 
       "valuesAndCounts": [
         [
           "changed.skp",