Fixing analyzer issues in DOM libs.

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..2414539ffc3befa7af0b01837e9a2b8a8baf4c83 100644
--- a/sdk/lib/html/html_common/filtered_element_list.dart
+++ b/sdk/lib/html/html_common/filtered_element_list.dart
@@ -69,7 +69,8 @@ class FilteredElementList implements List {
     return element is Element && _childNodes.contains(element);
   }
 
-  List<E> get reversed => new ReversedListView<E>(_filtered, 0, null);
+  List<Element> get reversed =>
+      new ReversedListView<Element>(_filtered, 0, null);
 
   void sort([int compare(Element a, Element b)]) {
     throw new UnsupportedError('TODO(jacobr): should we impl?');
@@ -125,19 +126,19 @@ 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,