Use 'pm clear' to clear application state.

build/android/pylib/android_commands.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.
 
 """Provides an interface to communicate with the device via the adb command.
 
 Assumes adb binary is currently on system path.
 """
 
 import collections
@@ skipping 623 matching lines @@
     """Attempt to close down the application, using increasing violence.
 
     Args:
       package: Name of the process to kill off, e.g.
       com.google.android.apps.chrome
     """
     self.RunShellCommand('am force-stop ' + package)
 
   def ClearApplicationState(self, package):
     """Closes and clears all state for the given |package|."""
-    self.CloseApplication(package)
-    self.RunShellCommand('su -c rm -r /data/data/%s/app_*' % package)
-    self.RunShellCommand('su -c rm -r /data/data/%s/cache/*' % package)
-    self.RunShellCommand('su -c rm -r /data/data/%s/files/*' % package)
-    self.RunShellCommand('su -c rm -r /data/data/%s/shared_prefs/*' % package)
+    # Check that the package exists before clearing it. Necessary because
+    # calling pm clear on a package that doesn't exist may never return.
+    pm_path_output  = self.RunShellCommand('pm path ' + package)
+    # The path output only contains anything if and only if the package exists.
+    if pm_path_output:
+      self.CloseApplication(package)
+      self.RunShellCommand('pm clear ' + package)
 
   def SendKeyEvent(self, keycode):
     """Sends keycode to the device.
 
     Args:
       keycode: Numeric keycode to send (see "enum" at top of file).
     """
     self.RunShellCommand('input keyevent %d' % keycode)
 
   def PushIfNeeded(self, local_path, device_path):
@@ skipping 559 matching lines @@
   """
   def __init__(self, output):
     self._output = output
 
   def write(self, data):
     data = data.replace('\r\r\n', '\n')
     self._output.write(data)
 
   def flush(self):
     self._output.flush()