depot_tools: add infra_paths recipe module for infra-specific paths

recipe_modules/infra_paths/config.py

Index: recipe_modules/infra_paths/config.py
diff --git a/recipe_modules/infra_paths/config.py b/recipe_modules/infra_paths/config.py
new file mode 100644
index 0000000000000000000000000000000000000000..e252912f299db6bff0d8d75b3cded3b1c47d5257
--- /dev/null
+++ b/recipe_modules/infra_paths/config.py
@@ -0,0 +1,50 @@
+# 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.config import config_item_context, ConfigGroup, Dict, Static
+from recipe_engine.config_types import Path
+
+def BaseConfig(PLATFORM, CURRENT_WORKING_DIR, ROOT, **_kwargs):
+  return ConfigGroup(
+    paths    = Dict(value_type=Path),
+
+    PLATFORM = Static(PLATFORM),
+    CURRENT_WORKING_DIR = Static(CURRENT_WORKING_DIR),
+    ROOT = Static(ROOT),
+  )
+
+config_ctx = config_item_context(BaseConfig)
+
+@config_ctx()
+def buildbot(c):
+  c.paths['root'] = c.ROOT.join('b')
+  c.paths['slave_build'] = c.CURRENT_WORKING_DIR
+  c.paths['cache'] = c.paths['root'].join(
+      'build', 'slave', 'cache')
+  c.paths['git_cache'] = c.paths['root'].join(
+      'build', 'slave', 'cache_dir')
+  c.paths['goma_cache'] = c.paths['root'].join(
+      'build', 'slave', 'goma_cache')
+  for token in ('build_internal', 'build', 'depot_tools'):
+    c.paths[token] = c.paths['root'].join(token,)
+
+@config_ctx()
+def kitchen(c):
+  c.paths['root'] = c.CURRENT_WORKING_DIR
+  c.paths['slave_build'] = c.CURRENT_WORKING_DIR
+  # TODO(phajdan.jr): have one cache dir, let clients append suffixes.
+  # TODO(phajdan.jr): set persistent cache path for remaining platforms.
+  # NOTE: do not use /b/swarm_slave here - it gets deleted on bot redeploy,
+  # and may happen even after a reboot.
+  if c.PLATFORM == 'linux':
+    c.paths['cache'] = c.ROOT.join(
+        'b', 'cache', 'chromium')
+    c.paths['git_cache'] = c.ROOT.join(
+        'b', 'cache', 'chromium', 'git_cache')
+    c.paths['goma_cache'] = c.ROOT.join(
+        'b', 'cache', 'chromium', 'goma_cache')
+  else:
+    c.paths['cache'] = c.paths['root'].join('cache')
+    c.paths['git_cache'] = c.paths['root'].join('cache_dir')
+    c.paths['goma_cache'] = c.paths['root'].join('goma_cache')