[Telemetry] Reorganize everything.

tools/telemetry/telemetry/core/chrome/platform.py

 # Copyright (c) 2012 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.
 
 class Platform(object):
   """The platform that the target browser is running on.
 
   Provides a limited interface to obtain stats from the platform itself, where
   possible.
   """
 
   def GetSurfaceCollector(self, trace_tag):
     """Platforms may be able to collect GL surface stats."""
     class StubSurfaceCollector(object):
       def __init__(self, trace_tag):
         pass
       def __enter__(self):
         pass
       def __exit__(self, *args):
         pass
 
     return StubSurfaceCollector(trace_tag)