[Android] Switch to DeviceUtils versions of file functions.

build/android/pylib/perf/thermal_throttle.py

Index: build/android/pylib/perf/thermal_throttle.py
diff --git a/build/android/pylib/perf/thermal_throttle.py b/build/android/pylib/perf/thermal_throttle.py
index 87ae9665a9d8a43522c430baa02f4c08f19a1c38..a125e72fbd78a2fb1f77397bf57a0ff9db86f6c5 100644
--- a/build/android/pylib/perf/thermal_throttle.py
+++ b/build/android/pylib/perf/thermal_throttle.py
@@ -14,8 +14,7 @@ class OmapThrottlingDetector(object):
 
   @staticmethod
   def IsSupported(device):
-    return device.old_interface.FileExistsOnDevice(
-        OmapThrottlingDetector.OMAP_TEMP_FILE)
+    return device.FileExists(OmapThrottlingDetector.OMAP_TEMP_FILE)
 
   def __init__(self, device):
     self._device = device
@@ -34,8 +33,7 @@ class OmapThrottlingDetector(object):
       return float([s for s in log_line.split() if s.isdigit()][0]) / 1000.0
 
   def GetCurrentTemperature(self):
-    tempdata = self._device.old_interface.GetFileContents(
-        OmapThrottlingDetector.OMAP_TEMP_FILE)
+    tempdata = self._device.ReadFile(OmapThrottlingDetector.OMAP_TEMP_FILE)
     return float(tempdata[0]) / 1000.0
 
 
@@ -43,7 +41,7 @@ class ExynosThrottlingDetector(object):
   """Class to detect and track thermal throttling on an Exynos 5."""
   @staticmethod
   def IsSupported(device):
-    return device.old_interface.FileExistsOnDevice('/sys/bus/exynos5-core')
+    return device.FileExists('/sys/bus/exynos5-core')
 
   def __init__(self, device):
     pass