depot_tools: add infra_paths recipe module for infra-specific paths (attempt #2)

recipe_modules/infra_paths/test_api.py

Index: recipe_modules/infra_paths/test_api.py
diff --git a/recipe_modules/infra_paths/test_api.py b/recipe_modules/infra_paths/test_api.py
deleted file mode 100644
index 3468ddf0ba41485c8a5d36c529cf7006d3b8f2b9..0000000000000000000000000000000000000000
--- a/recipe_modules/infra_paths/test_api.py
+++ /dev/null
@@ -1,16 +0,0 @@
-# Copyright 2016 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 recipe_engine import recipe_test_api
-from recipe_engine.config_types import Path, NamedBasePath
-
-class InfraPathsTestApi(recipe_test_api.RecipeTestApi): #pragma: no cover
-  @recipe_test_api.mod_test_data
-  @staticmethod
-  def exists(*paths):
-    assert all(isinstance(p, Path) for p in paths)
-    return paths
-
-  def __getitem__(self, name):
-    return Path(NamedBasePath(name))