[Telemetry][CodeHealth] Make unittests with fake platforms use fakes.FakePlatform

telemetry/telemetry/internal/story_runner_unittest.py

Index: telemetry/telemetry/internal/story_runner_unittest.py
diff --git a/telemetry/telemetry/internal/story_runner_unittest.py b/telemetry/telemetry/internal/story_runner_unittest.py
index 950c18460ea89714da92c6686a4fed5ea2a77385..24e2d9c0f4e7cc5b01f7aa62449658c4ac3cfade 100644
--- a/telemetry/telemetry/internal/story_runner_unittest.py
+++ b/telemetry/telemetry/internal/story_runner_unittest.py
@@ -44,23 +44,8 @@ from telemetry.wpr import archive_info
 
 # pylint: disable=too-many-lines
 
-class FakePlatform(object):
-  def CanMonitorThermalThrottling(self):
-    return False
-
-  def GetOSName(self):
-    pass
-
-  def WaitForBatteryTemperature(self, _):
-    pass
-
-  def GetDeviceTypeName(self):
-    return "GetDeviceTypeName"
 
 class TestSharedState(story_module.SharedState):
-
-  _platform = FakePlatform()
-
   @classmethod
   def SetTestPlatform(cls, platform):
     cls._platform = platform
@@ -70,6 +55,7 @@ class TestSharedState(story_module.SharedState):
         test, options, story_set)
     self._test = test
     self._current_story = None
+    self._platform = fakes.FakePlatform()
 
   @property
   def platform(self):
@@ -732,7 +718,7 @@ class StoryRunnerTest(unittest.TestCase):
       self, num_failing_stories, runner_max_failures, options_max_failures,
       expected_num_failures):
     class SimpleSharedState(story_module.SharedState):
-      _fake_platform = FakePlatform()
+      _fake_platform = fakes.FakePlatform()
       _current_story = None
 
       @property