Added integration tests for falling back from the HTTP proxy to direct.

tools/chrome_proxy/integration_tests/chrome_proxy_benchmark.py

 # Copyright 2014 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 integration_tests import chrome_proxy_measurements as measurements
 from integration_tests import chrome_proxy_pagesets as pagesets
 from telemetry import benchmark
 
 
 @benchmark.Enabled('android')
@@ skipping 99 matching lines @@
 
 
 @benchmark.Enabled('android')
 class ChromeProxyHTTPFallbackViaHeader(benchmark.Benchmark):
   tag = 'fallback-viaheader'
   test = measurements.ChromeProxyHTTPFallbackViaHeader
   page_set = pagesets.FallbackViaHeaderPageSet
 
 
 @benchmark.Enabled('android')
+class ChromeProxyHTTPToDirectFallback(benchmark.Benchmark):
+  tag = 'http-to-direct-fallback'
+  test = measurements.ChromeProxyHTTPToDirectFallback
+  page_set = pagesets.HTTPToDirectFallbackPageSet
+
+
+@benchmark.Enabled('android')
 class ChromeProxySmoke(benchmark.Benchmark):
   tag = 'smoke'
   test = measurements.ChromeProxySmoke
   page_set = pagesets.SmokePageSet