suppress checks for ebuild Manifests and caches

BUG=chromium-os:11308, chromium-os:21049
TEST=repo upload after adding a Manifest to a tree

Change-Id: I419e9664c50d2f6aecb4c505852a69e51114626b
Reviewed-on: http://gerrit.chromium.org/gerrit/10264
Reviewed-by: David James <davidjames@chromium.org>
Reviewed-by: Ryan Cui <rcui@chromium.org>
Reviewed-by: Brian Harring <ferringb@chromium.org>
Tested-by: Brian Harring <ferringb@chromium.org>
diff --git a/pre-upload.py b/pre-upload.py
index e7e643d..cf14647 100644
--- a/pre-upload.py
+++ b/pre-upload.py
@@ -36,6 +36,9 @@
   r".*\bexperimental[\\\/].*",
   r".*\b[A-Z0-9_]{2,}$",
   r".*[\\\/]debian[\\\/]rules$",
+  # for ebuild trees, ignore any caches and manifest data
+  r".*/Manifest$",
+  r".*/metadata/[^/]*cache[^/]*/[^/]+/[^/]+$",
 ]