Android: SurfaceStats cleanup (last side).

build/android/pylib/surface_stats_collector.py

Index: build/android/pylib/surface_stats_collector.py
diff --git a/build/android/pylib/surface_stats_collector.py b/build/android/pylib/surface_stats_collector.py
index ca41355cae703e75c704526b1c26f4aa180d4fb4..96da78b3d5a359da553d096c8dc9821c5196aadc 100644
--- a/build/android/pylib/surface_stats_collector.py
+++ b/build/android/pylib/surface_stats_collector.py
@@ -28,7 +28,7 @@ class SurfaceStatsCollector(object):
       self.value = value
       self.unit = unit
 
-  def __init__(self, adb, trace_tag=''):
+  def __init__(self, adb):
     self._adb = adb
     self._collector_thread = None
     self._use_legacy_method = False
@@ -38,9 +38,6 @@ class SurfaceStatsCollector(object):
     self._stop_event = None
     self._results = []
 
-  def __enter__(self):
-    self.Start()
-
   def Start(self):
     assert not self._collector_thread
 
@@ -54,9 +51,6 @@ class SurfaceStatsCollector(object):
       self._use_legacy_method = True
       self._surface_before = self._GetSurfaceStatsLegacy()
 
-  def __exit__(self, *args):
-    self.Stop()
-
   def Stop(self):
     self._StorePerfResults()
     if self._collector_thread: