[Android] Switch to DeviceUtils versions of file functions.

build/android/pylib/perf/perf_control.py

 # 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.
 
 import logging
 
 from pylib import android_commands
 from pylib.device import device_utils
 
 
 class PerfControl(object):
   """Provides methods for setting the performance mode of a device."""
   _SCALING_GOVERNOR_FMT = (
       '/sys/devices/system/cpu/cpu%d/cpufreq/scaling_governor')
   _CPU_ONLINE_FMT = '/sys/devices/system/cpu/cpu%d/online'
   _KERNEL_MAX = '/sys/devices/system/cpu/kernel_max'
 
   def __init__(self, device):
     # TODO(jbudorick) Remove once telemetry gets switched over.
     if isinstance(device, android_commands.AndroidCommands):
       device = device_utils.DeviceUtils(device)
     self._device = device
     cpu_files = self._device.RunShellCommand(
       'ls -d /sys/devices/system/cpu/cpu[0-9]*')
     self._num_cpu_cores = len(cpu_files)
     assert self._num_cpu_cores > 0, 'Failed to detect CPUs.'
     logging.info('Number of CPUs: %d', self._num_cpu_cores)
-    self._have_mpdecision = self._device.old_interface.FileExistsOnDevice(
-        '/system/bin/mpdecision')
+    self._have_mpdecision = self._device.FileExists('/system/bin/mpdecision')
 
   def SetHighPerfMode(self):
     # TODO(epenner): Enable on all devices (http://crbug.com/383566)
     if 'Nexus 4' == self._device.old_interface.GetProductModel():
       self._ForceAllCpusOnline(True)
       if not self._AllCpusAreOnline():
         logging.warning('Failed to force CPUs online. Results may be noisy!')
     self._SetScalingGovernorInternal('performance')
 
   def SetPerfProfilingMode(self):
@@ skipping 14 matching lines @@
         'Nexus 4': 'ondemand',
         'Nexus 7': 'interactive',
         'Nexus 10': 'interactive'
     }.get(product_model, 'ondemand')
     self._SetScalingGovernorInternal(governor_mode)
     self._ForceAllCpusOnline(False)
 
   def _SetScalingGovernorInternal(self, value):
     for cpu in range(self._num_cpu_cores):
       scaling_governor_file = PerfControl._SCALING_GOVERNOR_FMT % cpu
-      if self._device.old_interface.FileExistsOnDevice(scaling_governor_file):
+      if self._device.FileExists(scaling_governor_file):
         logging.info('Writing scaling governor mode \'%s\' -> %s',
                      value, scaling_governor_file)
-        self._device.old_interface.SetProtectedFileContents(
-            scaling_governor_file, value)
+        self._device.WriteFile(scaling_governor_file, value, as_root=True)
 
   def _AllCpusAreOnline(self):
     for cpu in range(self._num_cpu_cores):
       online_path = PerfControl._CPU_ONLINE_FMT % cpu
-      if self._device.old_interface.GetFileContents(online_path)[0] == '0':
+      if self._device.ReadFile(online_path)[0] == '0':
         return False
     return True
 
   def _ForceAllCpusOnline(self, force_online):
     """Enable all CPUs on a device.
 
     Some vendors (or only Qualcomm?) hot-plug their CPUs, which can add noise
     to measurements:
     - In perf, samples are only taken for the CPUs that are online when the
       measurement is started.
     - The scaling governor can't be set for an offline CPU and frequency scaling
       on newly enabled CPUs adds noise to both perf and tracing measurements.
 
     It appears Qualcomm is the only vendor that hot-plugs CPUs, and on Qualcomm
     this is done by "mpdecision".
 
     """
     if self._have_mpdecision:
       script = 'stop mpdecision' if force_online else 'start mpdecision'
       self._device.RunShellCommand(script, as_root=True)
 
     if not self._have_mpdecision and not self._AllCpusAreOnline():
       logging.warning('Unexpected cpu hot plugging detected.')
 
     if not force_online:
       return
 
     for cpu in range(self._num_cpu_cores):
       online_path = PerfControl._CPU_ONLINE_FMT % cpu
-      self._device.old_interface.SetProtectedFileContents(
-          online_path, '1')
+      self._device.WriteFile(online_path, '1', as_root=True)