Added support for improvement_direction to relevant values, which is propogated to chartjson.

tools/perf/benchmarks/speedometer.py

Index: tools/perf/benchmarks/speedometer.py
diff --git a/tools/perf/benchmarks/speedometer.py b/tools/perf/benchmarks/speedometer.py
index 96ca66bdc42b5c6de033752a04937f04376bb681..7007a439daeb9d58beb11345f0e06ddeb7893b1e 100644
--- a/tools/perf/benchmarks/speedometer.py
+++ b/tools/perf/benchmarks/speedometer.py
@@ -58,7 +58,8 @@ class SpeedometerMeasurement(page_test.PageTest):
         'benchmarkClient._finishedTestCount == benchmarkClient.testsCount', 600)
     results.AddValue(list_of_scalar_values.ListOfScalarValues(
         page, 'Total', 'ms',
-        tab.EvaluateJavaScript('benchmarkClient._timeValues'), important=True))
+        tab.EvaluateJavaScript('benchmarkClient._timeValues'), important=True,
+        higher_is_better=False))
 
     # Extract the timings for each suite
     for suite_name in self.enabled_suites:
@@ -71,7 +72,7 @@ class SpeedometerMeasurement(page_test.PageTest):
                     benchmarkClient._measuredValues[i].tests['%s'].total);
               };
               suite_times;
-              """ % suite_name), important=False))
+              """ % suite_name), important=False, higher_is_better=False))
 
 class Speedometer(benchmark.Benchmark):
   test = SpeedometerMeasurement