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

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

 # Copyright (c) 2012 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.
 
-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
 from telemetry.core import user_agent
 from telemetry.core import wpr_modes
 from telemetry.core import wpr_server
 from telemetry.core.chrome import extension_dict_backend
 from telemetry.core.chrome import tab_list_backend
 from telemetry.core.chrome import tracing_backend
 from telemetry.core.chrome import misc_web_contents_backend
@@ skipping 200 matching lines @@
     if ':sandboxed_process' in cmd_line:
       return 'renderer'
     m = re.match(r'.* --type=([^\s]*) .*', cmd_line)
     if not m:
       return 'browser'
     return m.group(1)
 
   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()
       self._tracing_backend = None
 
   def CreateForwarder(self, *port_pairs):
     raise NotImplementedError()
 
   def IsBrowserRunning(self):
     raise NotImplementedError()
 
   def GetStandardOutput(self):
     raise NotImplementedError()
 
 class DoNothingForwarder(object):
   def __init__(self, *port_pairs):
     self._host_port = port_pairs[0].local_port
 
   @property
   def url(self):
     assert self._host_port
     return 'http://127.0.0.1:%i' % self._host_port
 
   def Close(self):
     self._host_port = None