Add key_mobile_sites_cycler.py that contains page sets that does not do scrolling.

tools/perf/benchmarks/page_cycler.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 measurements import page_cycler
 import page_sets
 from telemetry import benchmark
 
 
 class _PageCycler(benchmark.Benchmark):
@@ skipping 161 matching lines @@
   page_set = page_sets.Top10MobilePageSet
 
   @classmethod
   def Name(cls):
     return 'page_cycler.top_10_mobile'
 
 
 @benchmark.Disabled
 class PageCyclerKeyMobileSites(_PageCycler):
   """Page load time benchmark for key mobile sites."""
-  page_set = page_sets.KeyMobileSitesSmoothPageSet
+  page_set = page_sets.KeyMobileSitesCyclerPageSet
 
   @classmethod
   def Name(cls):
     return 'page_cycler.key_mobile_sites_smooth'
 
 
 @benchmark.Disabled('android')  # crbug.com/357326
 class PageCyclerToughLayoutCases(_PageCycler):
   """Page loading for the slowest layouts observed in the Alexa top 1 million.
 
@@ skipping 21 matching lines @@
     return 'page_cycler.typical_25'
 
 
 @benchmark.Disabled # crbug.com/443730
 class PageCyclerBigJs(_PageCycler):
   page_set = page_sets.BigJsPageSet
   @classmethod
   def Name(cls):
     return 'page_cycler.big_js'