Revert "Add null initializers to fields that have no initializer."

lib/analyzer/ast_from_analyzer.dart

Index: lib/analyzer/ast_from_analyzer.dart
diff --git a/lib/analyzer/ast_from_analyzer.dart b/lib/analyzer/ast_from_analyzer.dart
index 24620fc510367252d8ff300f4736a7cb512d1098..17531457e2c28788c852a100700e186b3e577a26 100644
--- a/lib/analyzer/ast_from_analyzer.dart
+++ b/lib/analyzer/ast_from_analyzer.dart
@@ -2340,8 +2340,6 @@ class ClassBodyBuilder extends GeneralizingAstVisitor<Null> {
         buildDefaultConstructor(memberNode, defaultConstructor);
       }
     }
-
-    addDefaultFieldInitializers(classNode);
   }
 
   void buildDefaultConstructor(
@@ -2370,38 +2368,6 @@ class ClassBodyBuilder extends GeneralizingAstVisitor<Null> {
     }
   }
 
-  /// Adds initializers to fields that are have no initializer and are not
-  /// initialized by all constructors in the class.
-  void addDefaultFieldInitializers(ast.Class node) {
-    List<ast.Field> uninitializedFields = new List<ast.Field>();
-    for (var field in node.fields) {
-      if (field.initializer != null || field.isExternal) continue;
-      if (field.isStatic) {
-        field.initializer = new ast.NullLiteral()..parent = field;
-      } else {
-        uninitializedFields.add(field);
-      }
-    }
-    if (uninitializedFields.isEmpty) return;
-    constructorLoop:
-    for (var constructor in node.constructors) {
-      var remainingFields = uninitializedFields.toSet();
-      for (var initializer in constructor.initializers) {
-        if (initializer is ast.FieldInitializer) {
-          remainingFields.remove(initializer.field);
-        } else if (initializer is ast.RedirectingInitializer) {
-          // The target constructor will be checked in another iteration.
-          continue constructorLoop;
-        }
-      }
-      for (var field in remainingFields) {
-        if (field.initializer == null) {
-          field.initializer = new ast.NullLiteral()..parent = field;
-        }
-      }
-    }
-  }
-
   /// True for the `values` field of an `enum` class.
   static bool _isValuesField(FieldElement field) => field.name == 'values';