Reland of Don't bother running realpath in DeviceUtils._GetChangedAndStaleFiles()

build/android/pylib/device/device_utils.py

 # Copyright 2014 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.
 
 """Provides a variety of device interactions based on adb.
 
 Eventually, this will be based on adb_wrapper.
 """
 # pylint: disable=unused-argument
 
@@ skipping 1021 matching lines @@
       device_path: an absolute path of a file or directory on the device
       track_stale: whether to bother looking for stale files (slower)
 
     Returns:
       a three-element tuple
       1st element: a list of (host_files_path, device_files_path) tuples to push
       2nd element: a list of host_files_path that are up-to-date
       3rd element: a list of stale files under device_path, or [] when
         track_stale == False
     """
-    real_host_path = os.path.realpath(host_path)
     try:
-      real_device_path = self.RunShellCommand(
-          ['realpath', device_path], single_line=True, check_return=True)
-    except device_errors.CommandFailedError:
-      real_device_path = None
-    if not real_device_path:
-      return ([(host_path, device_path)], [], [])
-
-    try:
-      host_checksums = md5sum.CalculateHostMd5Sums([real_host_path])
-      interesting_device_paths = [real_device_path]
-      if not track_stale and os.path.isdir(real_host_path):
+      host_checksums = md5sum.CalculateHostMd5Sums([host_path])
+      interesting_device_paths = [device_path]
+      if not track_stale and os.path.isdir(host_path):
         interesting_device_paths = [
-            posixpath.join(real_device_path, os.path.relpath(p, real_host_path))
+            posixpath.join(device_path, os.path.relpath(p, host_path))
             for p in host_checksums.keys()]
       device_checksums = md5sum.CalculateDeviceMd5Sums(
           interesting_device_paths, self)
     except EnvironmentError as e:
       logging.warning('Error calculating md5: %s', e)
       return ([(host_path, device_path)], [], [])
 
     to_push = []
     up_to_date = []
     to_delete = []
     if os.path.isfile(host_path):
-      host_checksum = host_checksums.get(real_host_path)
-      device_checksum = device_checksums.get(real_device_path)
+      host_checksum = host_checksums.get(host_path)
+      device_checksum = device_checksums.get(device_path)
       if host_checksum == device_checksum:
         up_to_date.append(host_path)
       else:
         to_push.append((host_path, device_path))
     else:
       for host_abs_path, host_checksum in host_checksums.iteritems():
         device_abs_path = posixpath.join(
-            real_device_path, os.path.relpath(host_abs_path, real_host_path))
+            device_path, os.path.relpath(host_abs_path, host_path))
         device_checksum = device_checksums.pop(device_abs_path, None)
         if device_checksum == host_checksum:
           up_to_date.append(host_abs_path)
         else:
           to_push.append((host_abs_path, device_abs_path))
       to_delete = device_checksums.keys()
     return (to_push, up_to_date, to_delete)
 
   def _ComputeDeviceChecksumsForApks(self, package_name):
     ret = self._cache['package_apk_checksums'].get(package_name)
@@ skipping 803 matching lines @@
     return [cls(adb) for adb in adb_wrapper.AdbWrapper.Devices()
             if not blacklisted(adb)]
 
   @decorators.WithTimeoutAndRetriesFromInstance()
   def RestartAdbd(self, timeout=None, retries=None):
     logging.info('Restarting adbd on device.')
     with device_temp_file.DeviceTempFile(self.adb, suffix='.sh') as script:
       self.WriteFile(script.name, _RESTART_ADBD_SCRIPT)
       self.RunShellCommand(['source', script.name], as_root=True)
       self.adb.WaitForDevice()