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

tools/telemetry/unittest_data/page_tests/page_test3.py

Index: tools/telemetry/unittest_data/page_tests/page_test3.py
diff --git a/tools/telemetry/unittest_data/page_tests/page_test3.py b/tools/telemetry/unittest_data/page_tests/page_test3.py
new file mode 100644
index 0000000000000000000000000000000000000000..6ab807dc66f3c7d8c7b84551981bc31c140953d1
--- /dev/null
+++ b/tools/telemetry/unittest_data/page_tests/page_test3.py
@@ -0,0 +1,14 @@
+# 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.
+
+"""A simple PageTest used by page/record_wpr.py's unit tests."""
+
+from telemetry.page import page_test
+
+class MockPageTestThree(page_test.PageTest):
+  def __init__(self):
+    super(MockPageTestThree, self).__init__(action_name_to_run=None)
+
+  def ValidateAndMeasurePage(self, page, tab, results):
+    pass