Update Pica WPR and replace 'pica' benchmark with 'polymer_load.pica'

tools/perf/benchmarks/pica.py

Index: tools/perf/benchmarks/pica.py
diff --git a/tools/perf/benchmarks/pica.py b/tools/perf/benchmarks/pica.py
deleted file mode 100644
index ab33b9631191f6736ed7e6661cb12ce3d659c8ac..0000000000000000000000000000000000000000
--- a/tools/perf/benchmarks/pica.py
+++ /dev/null
@@ -1,24 +0,0 @@
-# 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.AddValue(scalar.ScalarValue(
-        results.current_page, 'Total', 'ms', result))
-
-
-class Pica(benchmark.Benchmark):
-  test = _PicaMeasurement
-  page_set = page_sets.PicaPageSet