Update pica to use results.AddValue(...)

tools/perf/benchmarks/pica.py

 # Copyright 2013 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.
 
 import page_sets
 from telemetry import benchmark
 from telemetry.page import page_measurement
+from telemetry.value import scalar
 
 class _PicaMeasurement(page_measurement.PageMeasurement):
   def CustomizeBrowserOptions(self, options):
     # Needed for native custom elements (document.register)
     options.AppendExtraBrowserArgs(
         '--enable-experimental-web-platform-features')
 
   def MeasurePage(self, _, tab, results):
     result = int(tab.EvaluateJavaScript('__polymer_ready_time'))
-    results.Add('Total', 'ms', result)
+    results.AddValue(scalar.ScalarValue(
+        results.current_page, 'Total', 'ms', result))
 
 
 class Pica(benchmark.Benchmark):
   test = _PicaMeasurement
   page_set = page_sets.PicaPageSet