Catching more errors when parsing ICE server URLs.

webrtc/base/stringencode.cc

Index: webrtc/base/stringencode.cc
diff --git a/webrtc/base/stringencode.cc b/webrtc/base/stringencode.cc
index 2930e5776c9015b1a70a5ef7246182e77f03a95d..01b41a633a2d70abeabb9c2a8e69af91b21f142a 100644
--- a/webrtc/base/stringencode.cc
+++ b/webrtc/base/stringencode.cc
@@ -556,7 +556,6 @@ std::string s_transform(const std::string& source, Transform t) {
 
 size_t tokenize(const std::string& source, char delimiter,
                 std::vector<std::string>* fields) {
-  RTC_DCHECK(fields);
   fields->clear();
   size_t last = 0;
   for (size_t i = 0; i < source.length(); ++i) {
@@ -573,6 +572,21 @@ size_t tokenize(const std::string& source, char delimiter,
   return fields->size();
 }
 
+size_t tokenize_with_empty_tokens(const std::string& source,
+                                  char delimiter,
+                                  std::vector<std::string>* fields) {
+  fields->clear();
+  size_t last = 0;
+  for (size_t i = 0; i < source.length(); ++i) {
+    if (source[i] == delimiter) {
+      fields->push_back(source.substr(last, i - last));
+      last = i + 1;
+    }
+  }
+  fields->push_back(source.substr(last, source.length() - last));
+  return fields->size();
+}
+
 size_t tokenize_append(const std::string& source, char delimiter,
                        std::vector<std::string>* fields) {
   if (!fields) return 0;