Modify all usage of PageMeasurement to use PageTest in tools/telemetry.

tools/telemetry/telemetry/benchmark.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 logging
 import optparse
 import os
 import shutil
 import sys
 import zipfile
@@ skipping 18 matching lines @@
   def __init__(self, name):
     self._name = name
 
   @property
   def name(self):
     return self._name
 
 class Benchmark(command_line.Command):
   """Base class for a Telemetry benchmark.
 
-  A test packages a PageTest/PageMeasurement and a PageSet together.
+  A test packages a PageTest and a PageSet together.
   """
   options = {}
 
   @classmethod
   def Name(cls):
     name = cls.__module__.split('.')[-1]
     if hasattr(cls, 'tag'):
       name += '.' + cls.tag
     if hasattr(cls, 'page_set'):
       name += '.' + cls.page_set.Name()
@@ skipping 154 matching lines @@
     """
     return test_expectations.TestExpectations()
 
 
 def AddCommandLineArgs(parser):
   page_runner.AddCommandLineArgs(parser)
 
 
 def ProcessCommandLineArgs(parser, args):
   page_runner.ProcessCommandLineArgs(parser, args)