infra_paths: keep cache paths super short to avoid long path issues

recipe_modules/infra_paths/path_config.py

 # 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.
 
 import DEPS
 CONFIG_CTX = DEPS['path'].CONFIG_CTX
 
 
 @CONFIG_CTX()
 def infra_common(c):
@@ skipping 18 matching lines @@
 def infra_kitchen(c):
   c.base_paths['root'] = c.CURRENT_WORKING_DIR
   c.base_paths['slave_build'] = c.CURRENT_WORKING_DIR
   # TODO(phajdan.jr): have one cache dir, let clients append suffixes.
 
   b_dir = c.CURRENT_WORKING_DIR
   while b_dir and b_dir[-1] != 'b':
     b_dir = b_dir[:-1]
 
   if c.PLATFORM in ('linux', 'mac'):
-    c.base_paths['cache'] = (
-        '/', 'b', 'cache', 'chromium')
-    for path in ('builder_cache', 'git_cache', 'goma_cache', 'goma_deps_cache'):
+    c.base_paths['cache'] = ('/', 'b', 'c')
+    c.base_paths['builder_cache'] = c.base_paths['cache'] + ('b',)
+    for path in ('git_cache', 'goma_cache', 'goma_deps_cache'):
       c.base_paths[path] = c.base_paths['cache'] + (path,)
   elif b_dir:
-    c.base_paths['cache'] = b_dir + ('cache', 'chromium')
-    for path in ('builder_cache', 'git_cache', 'goma_cache', 'goma_deps_cache'):
+    c.base_paths['cache'] = b_dir + ('c',)
+    c.base_paths['builder_cache'] = c.base_paths['cache'] + ('b',)
+    for path in ('git_cache', 'goma_cache', 'goma_deps_cache'):
       c.base_paths[path] = c.base_paths['cache'] + (path,)
   else:  # pragma: no cover
-    c.base_paths['cache'] = c.base_paths['root'] + ('cache',)
+    c.base_paths['cache'] = c.base_paths['root'] + ('c',)
+    c.base_paths['builder_cache'] = c.base_paths['cache'] + ('b',)
     c.base_paths['git_cache'] = c.base_paths['root'] + ('cache_dir',)
-    for path in ('builder_cache', 'goma_cache', 'goma_deps_cache'):
+    for path in ('goma_cache', 'goma_deps_cache'):
       c.base_paths[path] = c.base_paths['cache'] + (path,)