[Android] Clear gtest app's data on tear down.

build/android/pylib/gtest/test_package_apk.py

Index: build/android/pylib/gtest/test_package_apk.py
diff --git a/build/android/pylib/gtest/test_package_apk.py b/build/android/pylib/gtest/test_package_apk.py
index 84dd7bd8e746f0396e0ed49e9e9ded64fad081a5..7fb55f63a4af0ad88005fc343c2c08532f205793 100644
--- a/build/android/pylib/gtest/test_package_apk.py
+++ b/build/android/pylib/gtest/test_package_apk.py
@@ -87,6 +87,12 @@ class TestPackageApk(TestPackage):
   #override
   def ClearApplicationState(self, adb):
     adb.ClearApplicationState(self._test_apk_package_name)
+    # Content shell creates a profile on the sdscard which accumulates cache
+    # files over time.
+    if self.suite_name == 'content_browsertests':
+      adb.RunShellCommand(
+          'rm -r %s/content_shell' % adb.GetExternalStorage(),
+          timeout_time=60 * 2)
 
   #override
   def CreateCommandLineFileOnDevice(self, adb, test_filter, test_arguments):