telemetry: Add unit 'score' to 'mostly_smooth' metric.

tools/perf/metrics/smoothness.py

Index: tools/perf/metrics/smoothness.py
diff --git a/tools/perf/metrics/smoothness.py b/tools/perf/metrics/smoothness.py
index 2a5b96e2eccbaf961d8104bd564a7f2d2bbd88f3..a9acd07446d4a1dd5f1565560ae180dc0c28f5c6 100644
--- a/tools/perf/metrics/smoothness.py
+++ b/tools/perf/metrics/smoothness.py
@@ -79,7 +79,7 @@ class SmoothnessMetric(Metric):
     # Are we hitting 60 fps for 95 percent of all frames?
     # We use 19ms as a somewhat looser threshold, instead of 1000.0/60.0.
     percentile_95 = statistics.Percentile(self._stats.frame_times, 95.0)
-    results.Add('mostly_smooth', '', 1.0 if percentile_95 < 19.0 else 0.0)
+    results.Add('mostly_smooth', 'score', 1.0 if percentile_95 < 19.0 else 0.0)

[fmeawad, 2014/01/03 19:39:47]

Would '%' also work? is it a percentile?

[ernstm, 2014/01/04 01:08:47]

It is a binary value (0 or 1), so score seemed the best option from what we
already have in unit-info.json. Another reason why percent would not work is
that it is reported as 'lower is better'.

 
     if tab.browser.platform.IsRawDisplayFrameRateSupported():
       for r in tab.browser.platform.GetRawDisplayFrameRateMeasurements():