[Telemetry refactor] Drop "2" from method calls to JS API

tools/chrome_proxy/common/chrome_proxy_measurements.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.
 
 import base64
 import logging
 
 from common import chrome_proxy_metrics as metrics
 from telemetry.core import exceptions
 from telemetry.page import legacy_page_test
@@ skipping 33 matching lines @@
       '} catch (err) {'
         '/* Return normally if the xhr request failed. */'
       '}'
       'return false;'
     '}'
     '</script>'
     'Waiting for Chrome to start using the DRP...'
     '</body></html>'))
 
   # Ensure the page has finished loading before attempting the DRP check.
-  tab.WaitForJavaScriptCondition2('performance.timing.loadEventEnd', timeout=60)
+  tab.WaitForJavaScriptCondition('performance.timing.loadEventEnd', timeout=60)
 
   expected_via_header = metrics.CHROME_PROXY_VIA_HEADER
   if ChromeProxyValidation.extra_via_header:
     expected_via_header = ChromeProxyValidation.extra_via_header
 
-  tab.WaitForJavaScriptCondition2(
+  tab.WaitForJavaScriptCondition(
       'PollDRPCheck({{ url }}, {{ via_header }})',
       url=url, via_header=expected_via_header,
       timeout=60)
 
 
 class ChromeProxyValidation(legacy_page_test.LegacyPageTest):
   """Base class for all chrome proxy correctness measurements."""
 
   # Value of the extra via header. |None| if no extra via header is expected.
   extra_via_header = None
@@ skipping 24 matching lines @@
       WaitForViaHeader(tab)
 
     if self.clear_cache_before_each_run:
       tab.ClearCache(force=True)
     assert self._metrics
     self._metrics.Start(page, tab)
 
   def ValidateAndMeasurePage(self, page, tab, results):
     self._page = page
     # Wait for the load event.
-    tab.WaitForJavaScriptCondition2(
+    tab.WaitForJavaScriptCondition(
         'performance.timing.loadEventStart', timeout=300)
     assert self._metrics
     self._metrics.Stop(page, tab)
     if ChromeProxyValidation.extra_via_header:
       self._metrics.AddResultsForExtraViaHeader(
           tab, results, ChromeProxyValidation.extra_via_header)
     self.AddResults(tab, results)
 
   def AddResults(self, tab, results):
     raise NotImplementedError
 
   def StopBrowserAfterPage(self, browser, page):  # pylint: disable=W0613
     if hasattr(page, 'restart_after') and page.restart_after:
       return True
     return False