sandwich: Implements network condition on WPR server and browser.

tools/android/loading/device_setup.py

 # Copyright 2016 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 contextlib
 import logging
 import os
 import shutil
 import subprocess
 import sys
@@ skipping 87 matching lines @@
 
 
 def _SetUpDevice(device, package_info):
   """Enables root and closes Chrome on a device."""
   device.EnableRoot()
   device.KillAll(package_info.package, quiet=True)
 
 
 @contextlib.contextmanager
 def WprHost(device, wpr_archive_path, record=False,
+            network_condition_name=None,
             disable_script_injection=False):
   """Launches web page replay host.
 
   Args:
     device: Android device.
     wpr_archive_path: host sided WPR archive's path.
+    network_condition_name: Network condition name available in
+        chrome_setup.NETWORK_CONDITIONS.
     record: Enables or disables WPR archive recording.
 
   Returns:
     Additional flags list that may be used for chromium to load web page through
     the running web page replay host.
   """
   assert device
   if wpr_archive_path == None:
+    if record:
+      logging.error('WPR cannot record without a specified archive.')

[mattcary, 2016/02/19 15:40:17]

Do you want to assert rather than just logging an error? In many situations it's
better to not work at all rather than work incorrectly.

[gabadie, 2016/02/22 10:05:00]

Done.

+    if network_condition_name:
+      logging.error('WPR cannot emulate network condition without a specified' +
+                    'archive.')
     yield []
     return
 
   wpr_server_args = ['--use_closest_match']
   if record:
     wpr_server_args.append('--record')
     if os.path.exists(wpr_archive_path):
       os.remove(wpr_archive_path)
   else:
     assert os.path.exists(wpr_archive_path)
+  if network_condition_name:
+    condition = chrome_setup.NETWORK_CONDITIONS[network_condition_name]
+    if record:
+      logging.warning('WPR network condition is ignored when recording.')
+    else:
+      wpr_server_args.extend([
+          '--down', chrome_setup.BandwidthToString(condition['download']),
+          '--up', chrome_setup.BandwidthToString(condition['upload']),
+          '--delay_ms', str(condition['latency']),
+          '--shaping_type', 'proxy'])
 
   if disable_script_injection:
     # Remove default WPR injected scripts like deterministic.js which
     # overrides Math.random.
     wpr_server_args.extend(['--inject_scripts', ''])
 
   # Deploy certification authority to the device.
   temp_certificate_dir = tempfile.mkdtemp()
   wpr_ca_cert_path = os.path.join(temp_certificate_dir, 'testca.pem')
   certutils.write_dummy_ca_cert(*certutils.generate_dummy_ca_cert(),
@@ skipping 75 matching lines @@
                '--remote-debugging-port=%d' % OPTIONS.devtools_port]
   if OPTIONS.no_sandbox:
     new_flags.append('--no-sandbox')
   if additional_flags != None:
     new_flags.extend(additional_flags)
 
   if device:
     return _DevToolsConnectionOnDevice(device, new_flags)
   else:
     return chrome_setup.DevToolsConnectionForLocalBinary(new_flags)