[pylib/devil] Create devil.android.base_tool and derive valgrind_tools classes from it

build/android/devil/android/valgrind_tools/base_tool.py

+# Copyright (c) 2015 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.
+
+
+class BaseTool(object):
+  """A tool that does nothing."""
+  # pylint: disable=R0201
+
+  def __init__(self):
+    """Does nothing."""
+    pass
+
+  def GetTestWrapper(self):
+    """Returns a string that is to be prepended to the test command line."""
+    return ''
+
+  def GetUtilWrapper(self):
+    """Returns the wrapper name for the utilities.
+
+    Returns:
+       A string that is to be prepended to the command line of utility
+    processes (forwarder, etc.).
+    """
+    return ''
+
+  @classmethod
+  def CopyFiles(cls, device):
+    """Copies tool-specific files to the device, create directories, etc."""
+    pass
+
+  def SetupEnvironment(self):
+    """Sets up the system environment for a test.
+
+    This is a good place to set system properties.
+    """
+    pass
+
+  def CleanUpEnvironment(self):
+    """Cleans up environment."""
+    pass
+
+  def GetTimeoutScale(self):
+    """Returns a multiplier that should be applied to timeout values."""
+    return 1.0
+
+  def NeedsDebugInfo(self):
+    """Whether this tool requires debug info.
+
+    Returns:
+      True if this tool can not work with stripped binaries.
+    """
+    return False