Demote linux-386 to "best effort support", just like e.g. linux-ppc64.

It seems unfair to completely kill linux-386, while we still provide minimal
best-effort support for more exotic platforms like linux-ppc64 or linux-s390x.

R=iannucci@chromium.org, tandrii@chromium.org
BUG=854300

Change-Id: Ia31ebb42f7e596c495b09bb99ecb376801256d55
Reviewed-on: https://chromium-review.googlesource.com/1111026
Reviewed-by: Andrii Shyshkalov <tandrii@chromium.org>
Commit-Queue: Andrii Shyshkalov <tandrii@chromium.org>
Commit-Queue: Vadim Shtayura <vadimsh@chromium.org>
diff --git a/PRESUBMIT.py b/PRESUBMIT.py
index 343bd29..ebd5c2f 100644
--- a/PRESUBMIT.py
+++ b/PRESUBMIT.py
@@ -12,11 +12,13 @@
 import os
 
 
-ENSURE_FILE_TEMPLATE = r'''
-$VerifiedPlatform linux-amd64 linux-arm64 linux-armv6l linux-mips64
-$VerifiedPlatform linux-ppc64 linux-ppc64le linux-s390x
-$VerifiedPlatform mac-amd64
-$VerifiedPlatform windows-386 windows-amd64
+# CIPD ensure manifest for checking CIPD client itself.
+CIPD_CLIENT_ENSURE_FILE_TEMPLATE = r'''
+# Full supported.
+$VerifiedPlatform linux-amd64 mac-amd64 windows-amd64 windows-386
+# Best effort support.
+$VerifiedPlatform linux-386 linux-ppc64 linux-ppc64le linux-s390x
+$VerifiedPlatform linux-arm64 linux-armv6l linux-mips64
 
 %s %s
 '''
@@ -97,7 +99,8 @@
       pkg = 'infra/tools/cipd/${platform}'
       ver = input_api.ReadFile(path)
       tests.append(input_api.canned_checks.CheckCIPDManifest(
-          input_api, output_api, content=ENSURE_FILE_TEMPLATE % (pkg, ver)))
+          input_api, output_api,
+          content=CIPD_CLIENT_ENSURE_FILE_TEMPLATE % (pkg, ver)))
 
   results.extend(input_api.RunTests(tests))
   return results