Output units with histogram results.

The buildbot already understands them according to:
https://code.google.com/p/chromium/codesearch#chromium/tools/build/scripts/slave/process_log_utils.py

BUG=288231

Review URL: https://chromiumcodereview.appspot.com/23470006

git-svn-id: http://src.chromium.org/svn/trunk/src/build@222378 4ff67af0-8c30-449e-8e8b-ad334ec8d88c

android/pylib/perf_tests_helper.py

@@ -128,11 +128,12 @@ def PrintPerfResult(measurement, trace, values, units, result_type='default',
     # across different histograms.
     assert len(values) == 1
     value = values[0]
-    output = '%s%s: %s= %s' % (
+    output = '%s%s: %s= %s %s' % (
         RESULT_TYPES[result_type],
         _EscapePerfResult(measurement),
         trace_name,
-        value)
+        value,
+        units)
     avg, sd = GeomMeanAndStdDevFromHistogram(value)
 
   if avg: