Mock timer for Telemetry unit tests

tools/telemetry/telemetry/unittest/simple_mock.py

Index: tools/telemetry/telemetry/unittest/simple_mock.py
diff --git a/tools/telemetry/telemetry/unittest/simple_mock.py b/tools/telemetry/telemetry/unittest/simple_mock.py
index e468460f23718706138498d1affa9784ae4af838..b54dcac7231ef6337be6861d6bfc5b7f5c77441e 100644
--- a/tools/telemetry/telemetry/unittest/simple_mock.py
+++ b/tools/telemetry/telemetry/unittest/simple_mock.py
@@ -93,3 +93,14 @@ class MockObject(object):
       return expected_call.return_value
     handler.is_hook = True
     setattr(self, func_name, handler)
+
+
+class MockTimer(object):
+  def __init__(self):
+    self._elapsed_time = 0
+
+  def Sleep(self, time):
+    self._elapsed_time += time
+
+  def GetTime(self):
+    return self._elapsed_time