Add live tests for measuring data savings metrics

tools/chrome_proxy/live_tests/chrome_proxy_benchmark.py

Index: tools/chrome_proxy/live_tests/chrome_proxy_benchmark.py
diff --git a/tools/chrome_proxy/live_tests/chrome_proxy_benchmark.py b/tools/chrome_proxy/live_tests/chrome_proxy_benchmark.py
index a9a34ff379b7e1079b94c98a6e31d15cdf1d0c12..68e75c13bbe1e7a567b361fe8f0f249fefff275f 100644
--- a/tools/chrome_proxy/live_tests/chrome_proxy_benchmark.py
+++ b/tools/chrome_proxy/live_tests/chrome_proxy_benchmark.py
@@ -27,6 +27,16 @@ class ChromeProxyLatencyDirect(benchmark.Benchmark):
     return 'chrome_proxy_benchmark.latency_direct.top_20'
 
 
+class ChromeProxyLatencyMetrics(benchmark.Benchmark):
+  tag = 'latency_metrics'
+  test = measurements.ChromeProxyLatencyDirect
+  page_set = pagesets.MetricsStorySet
+
+  @classmethod
+  def Name(cls):
+    return 'chrome_proxy_benchmark.latency_metrics.metrics'
+
+
 class ChromeProxyDataSaving(benchmark.Benchmark):
   tag = 'data_saving'
   test = measurements.ChromeProxyDataSaving
@@ -46,3 +56,12 @@ class ChromeProxyDataSavingDirect(benchmark.Benchmark):
   def Name(cls):
     return 'chrome_proxy_benchmark.data_saving_direct.top_20'
 
+class ChromeProxyDataSavingMetrics(benchmark.Benchmark):
+  tag = 'data_saving_metrics'
+  test = measurements.ChromeProxyDataSavingDirect
+  page_set = pagesets.MetricsStorySet
+
+  @classmethod
+  def Name(cls):
+    return 'chrome_proxy_benchmark.data_saving_metrics.metrics'
+