[Android] Rework device filtering and add DeviceUtils.HealthyDevices.

build/android/pylib/device/device_filter.py

Index: build/android/pylib/device/device_filter.py
diff --git a/build/android/pylib/device/device_filter.py b/build/android/pylib/device/device_filter.py
deleted file mode 100644
index 8e54b2597635d8762fb9a52dcbf3ade0814a9734..0000000000000000000000000000000000000000
--- a/build/android/pylib/device/device_filter.py
+++ /dev/null
@@ -1,53 +0,0 @@
-# Copyright 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.
-
-from pylib.device import device_blacklist
-from pylib.device import device_errors
-
-
-def DefaultFilters():
-  """Returns a list of the most commonly-used device filters.
-
-  These filters match devices that:
-    - are in a "device" state (as opposed to, e.g., "unauthorized" or
-      "emulator")
-    - are not blacklisted.
-
-  Returns:
-    A list of the most commonly-used device filters.
-  """
-  return [DeviceFilter, BlacklistFilter()]
-
-
-def BlacklistFilter():
-  """Returns a filter that matches devices that are not blacklisted.
-
-  Note that this function is not the filter. It creates one when called using
-  the blacklist at that time and returns that.
-
-  Returns:
-    A filter function that matches devices that are not blacklisted.
-  """
-  blacklist = set(device_blacklist.ReadBlacklist())
-  def f(adb):
-    return adb.GetDeviceSerial() not in blacklist
-
-  return f
-
-
-def DeviceFilter(adb):
-  """A filter that matches devices in a "device" state.
-
-  (Basically, this is adb get-state == "device")
-
-  Args:
-    adb: An instance of AdbWrapper.
-  Returns:
-    True if the device is in a "device" state.
-  """
-  try:
-    return adb.GetState() == 'device'
-  except device_errors.CommandFailedError:
-    return False
-