Add warning batching in gclient_utils

gclient_utils.py

Index: gclient_utils.py
diff --git a/gclient_utils.py b/gclient_utils.py
index 7003fc88676b49e79aba8acbd5f68bdd2cdb7fd3..44dba57df2f8230c247e3bbf96eee5c58e61448c 100644
--- a/gclient_utils.py
+++ b/gclient_utils.py
@@ -27,6 +27,9 @@ RETRY_MAX = 3
 RETRY_INITIAL_SLEEP = 0.5
 
 
+_WARNINGS = []
+
+
 class Error(Exception):
   """gclient exception class."""
   def __init__(self, msg, *args, **kwargs):
@@ -36,6 +39,19 @@ class Error(Exception):
     super(Error, self).__init__(msg, *args, **kwargs)
 
 
+def PrintWarnings():
+  """Prints any accumulated warnings."""
+  if _WARNINGS:
+    print >> sys.stderr, '\n\nWarnings:'
+    for warning in _WARNINGS:
+      print >> sys.stderr, warning
+
+
+def AddWarning(msg):
+  """Adds the given warning message to the list of accumulated warnings."""
+  _WARNINGS.append(msg)
+
+
 def SplitUrlRevision(url):
   """Splits url and returns a two-tuple: url, rev"""
   if url.startswith('ssh:'):