Add perf tests for starting Chrome with URL

tools/perf/benchmarks/start_with_url.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.
+from telemetry import test
+
+from measurements import startup
+
+
+class StartWithUrlCold(test.Test):
+  """Measure time to start Chrome cold with startup URLs"""
+  tag = 'cold'
+  test = startup.Startup
+  page_set = 'page_sets/startup_pages.json'
+  options = {'cold': True,
+             'pageset_repeat_iters': 5}
+
+class StartWithUrlWarm(test.Test):
+  """Measure time to start Chrome warm with startup URLs"""
+  tag = 'warm'
+  test = startup.Startup
+  page_set = 'page_sets/startup_pages.json'
+  options = {'warm': True,
+             'pageset_repeat_iters': 10}
+