Fix bugs in GrowableList.remove*.

sdk/lib/html/html_common/filtered_element_list.dart

Index: sdk/lib/html/html_common/filtered_element_list.dart
diff --git a/sdk/lib/html/html_common/filtered_element_list.dart b/sdk/lib/html/html_common/filtered_element_list.dart
index a9cce44413ab449d919d18bd28aabc83c0d60a87..ff8d95c07ea7ecd356dfe1bdcf32b2ff2ce41de4 100644
--- a/sdk/lib/html/html_common/filtered_element_list.dart
+++ b/sdk/lib/html/html_common/filtered_element_list.dart
@@ -125,19 +125,19 @@ class FilteredElementList implements List {
 
   void removeAll(Iterable elements) {
     // This should be optimized to not use [remove] directly.
-    Collections.removeAll(this, elements);
+    IterableMixinWorkaround.removeAll(this, elements);
   }
 
   void retainAll(Iterable elements) {
-    Collections.retainAll(this, elements);
+    IterableMixinWorkaround.retainAll(this, elements);
   }
 
   void removeMatching(bool test(Element element)) {
-    Collections.removeMatching(this, test);
+    IterableMixinWorkaround.removeMatching(this, test);
   }
 
   void retainMatching(bool test(Element element)) {
-    Collections.retainMatching(this, test);
+    IterableMixinWorkaround.retainMatching(this, test);
   }
 
   dynamic reduce(dynamic initialValue,