Revert of [Android] Add a configurable environment for devil/. (RELAND 2)

build/android/pylib/constants/__init__.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.
 
 """Defines a set of constants shared by test runners and other scripts."""
 
 # TODO(jbudorick): Split these constants into coherent modules.
 
 # pylint: disable=W0212
 
 import collections
 import logging
 import os
 import subprocess
 
 import devil.android.sdk.keyevent
 from devil.android.sdk import version_codes
 from devil.constants import exit_codes
 
-
 keyevent = devil.android.sdk.keyevent
 
 
 DIR_SOURCE_ROOT = os.environ.get('CHECKOUT_SOURCE_ROOT',
     os.path.abspath(os.path.join(os.path.dirname(__file__),
                                  os.pardir, os.pardir, os.pardir, os.pardir)))
 
 PackageInfo = collections.namedtuple('PackageInfo',
     ['package', 'activity', 'cmdline_file', 'devtools_socket',
      'test_package'])
@@ skipping 206 matching lines @@
   """
   if 'CHROMIUM_OUTPUT_DIR' in os.environ:
     return os.path.abspath(os.path.join(
         DIR_SOURCE_ROOT, os.environ.get('CHROMIUM_OUTPUT_DIR')))
 
   return os.path.abspath(os.path.join(
       DIR_SOURCE_ROOT, os.environ.get('CHROMIUM_OUT_DIR', 'out'),
       GetBuildType() if build_type is None else build_type))
 
 
-# TODO(jbudorick): Convert existing callers to AdbWrapper.GetAdbPath() and
-# remove this.
+def _Memoize(func):
+  def Wrapper():
+    try:
+      return func._result
+    except AttributeError:
+      func._result = func()
+      return func._result
+  return Wrapper
+
+
+def SetAdbPath(adb_path):
+  os.environ['ADB_PATH'] = adb_path
+
+
 def GetAdbPath():
-  from devil.android.sdk import adb_wrapper
-  return adb_wrapper.AdbWrapper.GetAdbPath()
+  # Check if a custom adb path as been set. If not, try to find adb
+  # on the system.
+  if os.environ.get('ADB_PATH'):
+    return os.environ.get('ADB_PATH')
+  else:
+    return _FindAdbPath()
 
 
+@_Memoize
+def _FindAdbPath():
+  if os.environ.get('ANDROID_SDK_ROOT'):
+    return 'adb'
+  # If envsetup.sh hasn't been sourced and there's no adb in the path,
+  # set it here.
+  try:
+    with file(os.devnull, 'w') as devnull:
+      subprocess.call(['adb', 'version'], stdout=devnull, stderr=devnull)
+    return 'adb'
+  except OSError:
+    logging.debug('No adb found in $PATH, fallback to checked in binary.')
+    return os.path.join(ANDROID_SDK_ROOT, 'platform-tools', 'adb')
+
 # Exit codes
 ERROR_EXIT_CODE = exit_codes.ERROR
 INFRA_EXIT_CODE = exit_codes.INFRA
 WARNING_EXIT_CODE = exit_codes.WARNING