Android: splits cache_control and perf_control.

build/android/pylib/cache_control.py

Index: build/android/pylib/cache_control.py
diff --git a/build/android/pylib/cache_control.py b/build/android/pylib/cache_control.py
new file mode 100644
index 0000000000000000000000000000000000000000..6deaae382eb42705f26f82c008d41890bcfa7f67
--- /dev/null
+++ b/build/android/pylib/cache_control.py
@@ -0,0 +1,18 @@
+# Copyright (c) 2013 The Chromium Authors. All rights reserved.

[frankf, 2013/09/16 18:09:23]

Can we move all perf-specific modules to perf/ dir?

[dtu, 2013/09/16 18:36:59]

Feel free to put them in telemetry/core/platform/android or wherever else you
think fits.

[bulach, 2013/09/16 19:51:10]

good point, moved to build/android/pylib/perf

reason being that downstream has some dependencies to it and already depend on
pylib, so I wouldn't want to make them dependent on telemetry..

+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+import android_commands
+
+
+class CacheControl(object):
+  _DROP_CACHES = '/proc/sys/vm/drop_caches'
+
+  def __init__(self, adb):
+    self._adb = adb
+
+  def DropRamCaches(self):
+    """Drops the filesystem ram caches for performance testing."""
+    self._adb.RunShellCommand('su -c sync')

[frankf, 2013/09/16 18:09:23]

Can we add a RunShellCommandAsRoot('sync')?
It helps SEO :)

[bulach, 2013/09/16 19:51:10]

Done.

+    self._adb.SetProtectedFileContents(CacheControl._DROP_CACHES, '3')
+