[Telemetry] Add a page set option to use all cold page loads.

tools/telemetry/telemetry/core/chrome/browser_backend.py

Index: tools/telemetry/telemetry/core/chrome/browser_backend.py
diff --git a/tools/telemetry/telemetry/core/chrome/browser_backend.py b/tools/telemetry/telemetry/core/chrome/browser_backend.py
index 66c64dea9ba503d1d5e3d59530730af37ca6272e..e65c72bd9e788098a3a9558e6edd38854f16df66 100644
--- a/tools/telemetry/telemetry/core/chrome/browser_backend.py
+++ b/tools/telemetry/telemetry/core/chrome/browser_backend.py
@@ -2,12 +2,13 @@
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
-import urllib2
 import httplib
-import socket
+import logging
 import json
 import re
+import socket
 import sys
+import urllib2
 
 from telemetry.core import util
 from telemetry.core import exceptions
@@ -228,6 +229,25 @@ class BrowserBackend(object):
   def GetRemotePort(self, _):
     return util.GetAvailableLocalPort()
 
+  def CloseConnections(self):
+    tab = self._tab_list_backend[0]
+    try:
+      tab.ExecuteJavaScript("""window.chrome && chrome.benchmarking &&
+                               chrome.benchmarking.closeConnections();""")
+    except Exception:
+      pass
+
+  def ClearCache(self):
+    tab = self._tab_list_backend[0]
+    try:
+      tab.ExecuteJavaScript("""chrome.benchmarking.clearCache();
+                               chrome.benchmarking.clearHostResolverCache();
+                               chrome.benchmarking.clearPredictorCache();
+                               chrome.benchmarking.closeConnections();""")
+    except exceptions.EvaluateException:

[nduca, 2013/06/06 22:49:04]

this seems pretty funky, how do you know that this is supported? You really
should be thinking through this either being on all browsers, or doing is an
is_clear_cache_supported in the style of, for instance, screenshot.

[tonyg, 2013/06/20 02:42:29]

This is gone now.

+      logging.error('Failed to clear cache. Is --enable-net-benchmarking set?')
+      raise
+
   def Close(self):
     if self._tracing_backend:
       self._tracing_backend.Close()