Mock timer for Telemetry unit tests

tools/telemetry/telemetry/page/actions/gesture_action_unittest.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 time
-
 from telemetry.page.actions import gesture_action
+from telemetry.page.actions import wait
 from telemetry.unittest import tab_test_case
+from telemetry.unittest import simple_mock
 
 class MockGestureAction(gesture_action.GestureAction):
   """Mock gesture action that simply sleeps for a specified amount of time."""
-  def __init__(self, attributes=None):
+  def __init__(self, sleep_func, attributes=None):
+    self.sleep_func = sleep_func
     super(MockGestureAction, self).__init__(attributes)
 
   def RunGesture(self, page, tab):
     duration = getattr(self, 'duration', 2)
 
-    time.sleep(duration)
+    self.sleep_func(duration)
 
 
 class GestureActionTest(tab_test_case.TabTestCase):
   def testGestureAction(self):
     """Test that GestureAction.RunAction() calls RunGesture()."""
-    action = MockGestureAction({ 'duration': 1 })
+    mock_timer = simple_mock.MockTimer()
+    action = MockGestureAction(mock_timer.Sleep, { 'duration': 1 })
 
-    start_time = time.time()
     action.RunAction(None, self._tab)
-    self.assertGreaterEqual(time.time() - start_time, 1.0)
+    self.assertEqual(mock_timer.GetTime(), 1)
 
   def testWaitAfter(self):
-    action = MockGestureAction({ 'duration': 1,
-                                 'wait_after': { 'seconds': 1 } })
+    mock_timer = simple_mock.MockTimer()
+    real_time_sleep = wait.time.sleep
+    wait.time.sleep = mock_timer.Sleep
 
-    start_time = time.time()
-    action.RunAction(None, self._tab)
-    self.assertGreaterEqual(time.time() - start_time, 2.0)
+    try:
+      action = MockGestureAction(mock_timer.Sleep,
+                                 { 'duration': 1,
+                                   'wait_after': { 'seconds': 1 } })
+
+      action.RunAction(None, self._tab)
+      self.assertEqual(mock_timer.GetTime(), 2)
+    finally:
+      wait.time.sleep = real_time_sleep