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

build/android/devil/android/sdk/aapt.py

Index: build/android/devil/android/sdk/aapt.py
diff --git a/build/android/devil/android/sdk/aapt.py b/build/android/devil/android/sdk/aapt.py
index 1c051e0c55fbe3f232891ef1ecc26d26fcbe892f..7ae3a9380afc0d5feb364b727b8f5413407fe754 100644
--- a/build/android/devil/android/sdk/aapt.py
+++ b/build/android/devil/android/sdk/aapt.py
@@ -4,12 +4,13 @@
 
 """This module wraps the Android Asset Packaging Tool."""
 
-import os
-
+from devil.android.sdk import build_tools
 from devil.utils import cmd_helper
-from pylib import constants
+from devil.utils import lazy
+
+
+_aapt_path = lazy.WeakConstant(lambda: build_tools.GetPath('aapt'))
 
-_AAPT_PATH = os.path.join(constants.ANDROID_SDK_TOOLS, 'aapt')
 
 def _RunAaptCmd(args):
   """Runs an aapt command.
@@ -20,13 +21,14 @@ def _RunAaptCmd(args):
   Returns:
     The output of the command.
   """
-  cmd = [_AAPT_PATH] + args
+  cmd = [_aapt_path.read()] + args
   status, output = cmd_helper.GetCmdStatusAndOutput(cmd)
   if status != 0:
     raise Exception('Failed running aapt command: "%s" with output "%s".' %
                     (' '.join(cmd), output))
   return output
 
+
 def Dump(what, apk, assets=None):
   """Returns the output of the aapt dump command.