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

tools/perf/metrics/system_memory.py

 # Copyright 2014 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 from metrics import memory
 from metrics import Metric
 from telemetry.value import scalar
 
 
 class SystemMemoryMetric(Metric):
@@ skipping 46 matching lines @@
       return
     exclude_metrics = exclude_metrics or {}
     memory.AddResultsForProcesses(results, memory_stats,
         metric_trace_name=trace_name, chart_trace_name='delta',
         exclude_metrics=exclude_metrics)
 
     if 'SystemCommitCharge' not in exclude_metrics:
       results.AddValue(scalar.ScalarValue(
           results.current_page,
           'commit_charge_delta.%s' % (trace_name or 'commit_charge'), 'kb',
-          memory_stats['SystemCommitCharge'], important=False))
+          memory_stats['SystemCommitCharge'], important=False,
+          higher_is_better=False))
 
     if 'ProcessCount' not in exclude_metrics:
       results.AddValue(scalar.ScalarValue(
           results.current_page,
           'processes_delta.%s' % (trace_name or 'processes'), 'count',
-          memory_stats['ProcessCount'], important=False))
+          memory_stats['ProcessCount'], important=False,
+          higher_is_better=False))
 
 
 def _SubtractMemoryStats(end_memory_stats, start_memory_stats):
   """Computes the difference in memory usage stats.
 
   Each of the two stats arguments is a dict with the following format:
       {'Browser': {metric: value, ...},
        'Renderer': {metric: value, ...},
        'Gpu': {metric: value, ...},
        'ProcessCount': value,
@@ skipping 31 matching lines @@
       memory_stats[process_type] = end_process_memory - start_value
     else:
       for metric in end_process_memory:
         end_value = end_process_memory[metric]
         start_value = start_memory_stats[process_type][metric] or 0
         if 'Peak' in metric:
           memory_stats[process_type][metric] = end_value
         else:
           memory_stats[process_type][metric] = end_value - start_value
   return memory_stats