[Android] Add a configurable environment for devil/.

build/android/devil/env/dependency_config.py

Index: build/android/devil/env/dependency_config.py
diff --git a/build/android/devil/env/dependency_config.py b/build/android/devil/env/dependency_config.py
new file mode 100644
index 0000000000000000000000000000000000000000..5d2f696fe03d2575cb41a3d744d8b6ee565dbd54
--- /dev/null
+++ b/build/android/devil/env/dependency_config.py
@@ -0,0 +1,18 @@
+# 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.
+
+import os
+
+from devil.env import env_config
+
+DEVIL_PYMOCK_PATH = 'DEVIL_PYMOCK_PATH'
+
+
+class DependencyConfig(env_config.EnvConfig):
+
+  @property
+  def pymock_path(self):
+    return (self._configured.get('pymock_path')
+            or os.environ.get(DEVIL_PYMOCK_PATH))
+