Use iterator, moveNext(), current.

pkg/unittest/lib/mock.dart

Index: pkg/unittest/lib/mock.dart
diff --git a/pkg/unittest/lib/mock.dart b/pkg/unittest/lib/mock.dart
index 9ddab17bb7bef70eb42e37982cfc2945c172ba63..2418d85217e5b5a009af400f799877d77091a786 100644
--- a/pkg/unittest/lib/mock.dart
+++ b/pkg/unittest/lib/mock.dart
@@ -844,8 +844,9 @@ class LogEntryList {
       remainingCount = logs.length;
     }
 
-    var keyIterator = keys.logs.iterator();
-    LogEntry keyEntry = keyIterator.next();
+    var keyIterator = keys.logs.iterator;
+    keyIterator.moveNext();
+    LogEntry keyEntry = keyIterator.current;
     MatchState matchState = new MatchState();
 
     for (LogEntry logEntry in logs) {
@@ -869,8 +870,8 @@ class LogEntryList {
         if (includeKeys) {
           rtn.logs.add(keyEntry);
         }
-        if (keyIterator.hasNext) {
-          keyEntry = keyIterator.next();
+        if (keyIterator.moveNext()) {
+          keyEntry = keyIterator.current;
         } else if (isPreceding) { // We're done.
           break;
         }