Add test to compare-failures

tools/gardening/lib/src/buildbot_structures.dart

Index: tools/gardening/lib/src/buildbot_structures.dart
diff --git a/tools/gardening/lib/src/buildbot_structures.dart b/tools/gardening/lib/src/buildbot_structures.dart
index 3cbd500689e636ec6d8fe1607dede5edeffdda76..3e198b32361e91bce1ea0e9ce859c7e0cfebfd50 100644
--- a/tools/gardening/lib/src/buildbot_structures.dart
+++ b/tools/gardening/lib/src/buildbot_structures.dart
@@ -166,8 +166,8 @@ class TestFailure {
     String testName = parts[3];
     TestConfiguration id =
         new TestConfiguration(configName, archName, testName);
-    String expected = split(lines[1], ['Expected: '])[1];
-    String actual = split(lines[2], ['Actual: '])[1];
+    String expected = split(lines[1], ['Expected: '])[1].trim();
+    String actual = split(lines[2], ['Actual: '])[1].trim();
     return new TestFailure.internal(
         uri, id, expected, actual, lines.skip(3).join('\n'));
   }