[telemetry] Move telemetry/core/chrome/ to telemetry/core/backends/chrome/

tools/telemetry/telemetry/core/backends/chrome/cros_interface.py

-# Copyright (c) 2012 The Chromium Authors. All rights reserved.
+# Copyright 2013 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.
 """A wrapper around ssh for common operations on a CrOS-based device"""
 import logging
 import os
 import re
 import subprocess
 import sys
 import tempfile
 
@@ skipping 324 matching lines @@
                          (SCREENSHOT_DIR, screenshot_prefix, i, SCREENSHOT_EXT))
       if not self.FileExistsOnDevice(screenshot_file):
         self.RunCmdOnDevice([
             'DISPLAY=:0.0 XAUTHORITY=/home/chronos/.Xauthority '
             '/usr/local/bin/import',
             '-window root',
             '-depth 8',
             screenshot_file])
         return
     logging.warning('screenshot directory full.')