Add loading mobile story set

tools/perf/benchmarks/page_cycler_v2.py

Index: tools/perf/benchmarks/page_cycler_v2.py
diff --git a/tools/perf/benchmarks/page_cycler_v2.py b/tools/perf/benchmarks/page_cycler_v2.py
index 68b8e27a3cda2dc72fde3be6d4f8336f3f08c104..dd017094bba43a65862ac6c5b817f8a4d3b6ed86 100644
--- a/tools/perf/benchmarks/page_cycler_v2.py
+++ b/tools/perf/benchmarks/page_cycler_v2.py
@@ -215,3 +215,15 @@ class PageCyclerV2BasicOopif(_PageCyclerV2):
   def CreateStorySet(self, options):
     return page_sets.OopifBasicPageSet(cache_temperatures=[
           cache_temperature.PCV1_COLD, cache_temperature.PCV1_WARM])
+
+
+class PageCyclerV2LoadingMobile(_PageCyclerV2):
+  """ A benchmark measuring loading performance of mobile sites. """
+
+  @classmethod
+  def Name(cls):
+    return 'page_cycler_v2.loading_mobile'
+
+  def CreateStorySet(self, options):
+    return page_sets.LoadingMobileStorySet(cache_temperatures=[
+          cache_temperature.PCV1_COLD, cache_temperature.PCV1_WARM])