Add Web Components page sets and benchmark

tools/perf/benchmarks/web_components.py

+# Copyright 2017 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 benchmarks import page_cycler_v2
+from core import perf_benchmark
+from telemetry import benchmark
+from telemetry.web_perf import timeline_based_measurement
+import page_sets
+
+
+# Disabled because we do not plan on running CT benchmarks on the perf
+# waterfall any time soon.
+@benchmark.Disabled('all')
+@benchmark.Owner(emails=['hayato@chromium.org'])
+class WebComponents(perf_benchmark.PerfBenchmark):
+
+  options = {'pageset_repeat': 3}
+  page_set = page_sets.WebComponentsPageSet
+
+  def CreateTimelineBasedMeasurementOptions(self):
+    tbm_options = timeline_based_measurement.Options()
+    page_cycler_v2.AugmentOptionsForLoadingMetrics(tbm_options)
+    tbm_options.SetTimelineBasedMetrics(['loadingMetric'])
+    return tbm_options
+
+  @classmethod
+  def Name(cls):
+    return 'web_components.web_components'