message: Fix time units in plotted charts
  Cr-Commit-Position: refs/heads/master@{#29183}
diff: @@ -62,7 +62,7 @@ def main():
  y_values.append(sample['value'])
  plt.ylabel('%s (%s)' % (metric[GRAPH_NAME], metric[UNITS]))
  - plt.xlabel('time (ms)')
  + plt.xlabel('time (s)')
  plt.title(metric[GRAPH_NAME])
  plt.plot(x_values, y_values)
  