[Telemetry] Refactor mac power monitoring to use the base PowerMonitor class.

tools/telemetry/telemetry/core/platform/__init__.py

Index: tools/telemetry/telemetry/core/platform/__init__.py
diff --git a/tools/telemetry/telemetry/core/platform/__init__.py b/tools/telemetry/telemetry/core/platform/__init__.py
index 3a7ee8bc96ffe931f334ed0eb20896afea04b5fd..79291c2b1cc9fdacfa0f63a218b31f2fe54cc7e8 100644
--- a/tools/telemetry/telemetry/core/platform/__init__.py
+++ b/tools/telemetry/telemetry/core/platform/__init__.py
@@ -2,12 +2,6 @@
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
-import sys
-
-from telemetry.core.platform import linux_platform_backend
-from telemetry.core.platform import mac_platform_backend
-from telemetry.core.platform import win_platform_backend
-
 class Platform(object):
   """The platform that the target browser is running on.
 
@@ -233,14 +227,3 @@ class Platform(object):
       }
     """
     return self._platform_backend.StopMonitoringPowerAsync()
-
-
-def CreatePlatformBackendForCurrentOS():
-  if sys.platform.startswith('linux'):
-    return linux_platform_backend.LinuxPlatformBackend()
-  elif sys.platform == 'darwin':
-    return mac_platform_backend.MacPlatformBackend()
-  elif sys.platform == 'win32':
-    return win_platform_backend.WinPlatformBackend()
-  else:
-    raise NotImplementedError()