[ChromeDriver] Implementing tracing support

chrome/test/chromedriver/client/chromedriver.py

 # Copyright 2013 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 command_executor
 from command_executor import Command
 from webelement import WebElement
 
 
 class ChromeDriverException(Exception):
@@ skipping 47 matching lines @@
 
 
 class ChromeDriver(object):
   """Starts and controls a single Chrome instance on this machine."""
 
   def __init__(self, server_url, chrome_binary=None, android_package=None,
                android_activity=None, android_process=None,
                android_use_running_app=None, chrome_switches=None,
                chrome_extensions=None, chrome_log_path=None,
                debugger_address=None, browser_log_level=None,
-               mobile_emulation=None, experimental_options=None):
+               performance_log_level=None, mobile_emulation=None,
+               experimental_options=None):
     self._executor = command_executor.CommandExecutor(server_url)
 
     options = {}
 
     if experimental_options:
       assert isinstance(experimental_options, dict)
       options = experimental_options.copy()
 
     if android_package:
       options['androidPackage'] = android_package
@@ skipping 24 matching lines @@
 
     if debugger_address:
       assert type(debugger_address) is str
       options['debuggerAddress'] = debugger_address
 
     logging_prefs = {}
     log_levels = ['ALL', 'DEBUG', 'INFO', 'WARNING', 'SEVERE', 'OFF']
     if browser_log_level:
       assert browser_log_level in log_levels
       logging_prefs['browser'] = browser_log_level
+    if performance_log_level:
+      assert performance_log_level in log_levels
+      logging_prefs['performance'] = performance_log_level
 
     params = {
       'desiredCapabilities': {
         'chromeOptions': options,
         'loggingPrefs': logging_prefs
       }
     }
 
     response = self._ExecuteCommand(Command.NEW_SESSION, params)
     self._session_id = response['sessionId']
@@ skipping 212 matching lines @@
     return self.ExecuteCommand(Command.GET_LOG, {'type': type})
 
   def GetAvailableLogTypes(self):
     return self.ExecuteCommand(Command.GET_AVAILABLE_LOG_TYPES)
 
   def IsAutoReporting(self):
     return self.ExecuteCommand(Command.IS_AUTO_REPORTING)
 
   def SetAutoReporting(self, enabled):
     self.ExecuteCommand(Command.SET_AUTO_REPORTING, {'enabled': enabled})