Fix histogram printing for Telemetry tests.

build/android/pylib/perf_tests_helper.py

Index: build/android/pylib/perf_tests_helper.py
diff --git a/build/android/pylib/perf_tests_helper.py b/build/android/pylib/perf_tests_helper.py
index e09221bbf930941fbf1d1a0c09ed6dad073f1587..f320e4f1b64c6cbbbb6a293f09e4f4059489adeb 100644
--- a/build/android/pylib/perf_tests_helper.py
+++ b/build/android/pylib/perf_tests_helper.py
@@ -61,6 +61,7 @@ def _MeanAndStdDevFromList(values):
       value = ", ".join(values)
   else:
     value = values[0]
+    avg = values[0]
   return value, avg, sd
 
 
@@ -87,28 +88,43 @@ def PrintPerfResult(measurement, trace, values, units, result_type='default',
   """
   assert result_type in RESULT_TYPES, 'result type: %s is invalid' % result_type
 
-  if result_type in ['unimportant', 'default', 'informational']:
+  trace_name = _EscapePerfResult(trace)
+  if result_type in ['histogram', 'unimportant-histogram']:
     assert isinstance(values, list)
     assert len(values)
-    assert '/' not in measurement
-    value, avg, sd = _MeanAndStdDevFromList(values)
+    # Print out each histogram separately. We can't print the units, otherwise
+    # the histogram json output can't be parsed easily.
+    output = ''
+    ix = 1
+    for value in values:
+      name = '%s.%s_%d' % (_EscapePerfResult(measurement), trace_name, ix)
+      output += '%s%s%s : %s = %s' % (
+          '\n' if ix > 1 else '',
+          RESULT_TYPES[result_type],
+          name,
+          name,
+          value)
+      ix += 1
+    means_and_sds = [GeomMeanAndStdDevFromHistogram(value) for value in values]
+    print means_and_sds
+    _, avg, sd = _MeanAndStdDevFromList([mean for (mean, _) in means_and_sds ])
   else:
-    value = values[0]
-    # We can't print the units, otherwise parsing the histogram json output
-    # can't be parsed easily.
-    units = ''
-    avg, sd = GeomMeanAndStdDevFromHistogram(value)
-
-  trace_name = _EscapePerfResult(trace)
-  output = '%s%s: %s%s%s %s' % (
-    RESULT_TYPES[result_type],
-    _EscapePerfResult(measurement),
-    trace_name,
-    # Do not show equal sign if the trace is empty. Usually it happens when
-    # measurement is enough clear to describe the result.
-    '= ' if trace_name else '',
-    value,
-    units)
+    if result_type in ['unimportant', 'default', 'informational']:
+      assert isinstance(values, list)
+      assert len(values)
+      assert '/' not in measurement
+      value, avg, sd = _MeanAndStdDevFromList(values)
+    else:
+      value = values[0]

[bulach, 2012/11/22 18:21:59]

nit: is this possible to reach this? my understanding was that it's either one
of the three values in 112, or from 92, and it'd assert that it's a non-empty
list..
so probably best to do an elif at 111 and remove 117/118 altogether.. how does
it sound?

[marja, 2012/11/23 09:08:33]

Done. Yes, I had misinterpreted the association of this else, so this was wrong
again...

+    output = '%s%s: %s%s%s %s' % (
+        RESULT_TYPES[result_type],
+        _EscapePerfResult(measurement),
+        trace_name,
+        # Do not show equal sign if the trace is empty. Usually it happens when
+        # measurement is enough clear to describe the result.
+        '= ' if trace_name else '',
+        value,
+        units)
   if avg:
     output += '\nAvg %s: %f%s' % (measurement, avg, units)
   if sd: