Revert "Construct literal maps using factory constructor."

sdk/lib/_internal/lib/collection_patch.dart

Index: sdk/lib/_internal/lib/collection_patch.dart
diff --git a/sdk/lib/_internal/lib/collection_patch.dart b/sdk/lib/_internal/lib/collection_patch.dart
index a7e7ee25f3029aa7ece7e59f3827117d9b2c11c8..192dfd3e398506236c35b4e50febec5d529b840b 100644
--- a/sdk/lib/_internal/lib/collection_patch.dart
+++ b/sdk/lib/_internal/lib/collection_patch.dart
@@ -4,7 +4,6 @@
 
 // Patch file for dart:collection classes.
 import 'dart:_foreign_helper' show JS;
-import 'dart:_js_helper' show fillLiteralMap, NoInline;
 
 patch class HashMap<K, V> {
   patch factory HashMap({ bool equals(K key1, K key2),
@@ -489,18 +488,6 @@ patch class LinkedHashMap<K, V> {
   }
 
   patch factory LinkedHashMap.identity() = _LinkedIdentityHashMap<K, V>;
-
-  // Private factory constructor called by generated code for map literals.
-  @NoInline()
-  factory LinkedHashMap._literal(List keyValuePairs) {
-    return fillLiteralMap(keyValuePairs, new _LinkedHashMap<K, V>());
-  }
-
-  // Private factory constructor called by generated code for map literals.
-  @NoInline()
-  factory LinkedHashMap._empty() {
-    return new _LinkedHashMap<K, V>();
-  }
 }
 
 class _LinkedHashMap<K, V> implements LinkedHashMap<K, V> {