Update from https://crrev.com/305340

build/android/pylib/perf/perf_control_unittest.py

Index: build/android/pylib/perf/perf_control_unittest.py
diff --git a/build/android/pylib/perf/perf_control_unittest.py b/build/android/pylib/perf/perf_control_unittest.py
index aa31f68d010531ab2ff84fbfd1bd25e90f25b565..dd7cb88002cbd73c2ead71bcfa9a16383231f1c0 100644
--- a/build/android/pylib/perf/perf_control_unittest.py
+++ b/build/android/pylib/perf/perf_control_unittest.py
@@ -27,13 +27,11 @@ class TestPerfControl(unittest.TestCase):
     perf = perf_control.PerfControl(self._device)
     try:
       perf.SetPerfProfilingMode()
-      for cpu in range(perf._num_cpu_cores):
-        path = perf_control.PerfControl._CPU_ONLINE_FMT % cpu
-        self.assertEquals('1',
-                          self._device.ReadFile(path)[0])
-        path = perf_control.PerfControl._SCALING_GOVERNOR_FMT % cpu
-        self.assertEquals('performance',
-                          self._device.ReadFile(path)[0])
+      cpu_info = perf.GetCpuInfo()
+      self.assertEquals(len(perf._cpu_files), len(cpu_info))
+      for _, online, governor in cpu_info:
+        self.assertTrue(online)
+        self.assertEquals('performance', governor)
     finally:
       perf.SetDefaultPerfMode()