[android] Clear content_browsertests profile after each run.

build/android/pylib/gtest/test_runner.py

 # Copyright (c) 2012 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
 import os
 import re
 
 from pylib import android_commands
 from pylib import constants
@@ skipping 169 matching lines @@
   def SetUp(self):
     """Sets up necessary test enviroment for the test suite."""
     super(TestRunner, self).SetUp()
     if _TestSuiteRequiresMockTestServer(self.test_package.suite_name):
       self.LaunchChromeTestServerSpawner()
     self.tool.SetupEnvironment()
 
   #override
   def TearDown(self):
     """Cleans up the test enviroment for the test suite."""
+    # Content shell creates a profile on the sdscard which accumulates cache
+    # files over time.
+    self.adb.RunShellCommand('rm -r ' +
+        os.path.join(self.adb.GetExternalStorage(), 'content_shell'),
+        timeout_time=60 * 2)
     self.tool.CleanUpEnvironment()
     super(TestRunner, self).TearDown()