Speculative fix for official build failures

The builds are failing to find the 'utf-8' codec. This should
hopefully help fixing the problem.

Bug: 999461
Change-Id: I1d021974c12aab2ff365dcd95d87dc3ace5c1b70
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1779439Reviewed-by: Robert Sesek <rsesek@chromium.org>
Commit-Queue: Stephen Martinis <martiniss@chromium.org>
Cr-Commit-Position: refs/heads/master@{#692285}

build/config/ios/codesign.py

@@ -3,6 +3,7 @@
 # found in the LICENSE file.
 
 import argparse
+import codecs
 import datetime
 import fnmatch
 import glob
@@ -510,6 +511,10 @@ class GenerateEntitlementsAction(Action):
 
 
 def Main():
+  # Cache this codec so that plistlib can find it. See
+  # https://crbug.com/999461#c12 for more details.
+  codecs.lookup('utf-8')
+
   parser = argparse.ArgumentParser('codesign iOS bundles')
   subparsers = parser.add_subparsers()