strong_mode.dart: remove extra asserts and throw

pkg/analyzer/lib/src/task/dart.dart

 // Copyright (c) 2015, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 library analyzer.src.task.dart;
 
 import 'dart:collection';
 
 import 'package:analyzer/dart/element/element.dart';
 import 'package:analyzer/dart/element/type.dart';
@@ skipping 3197 matching lines @@
       visitor.initForIncrementalResolution();
       initializer.accept(visitor);
 
       //
       // Record the type of the variable.
       //
       DartType newType = initializer.staticType;
       if (newType == null || newType.isBottom) {
         newType = typeProvider.dynamicType;
       }
-      variable.type = newType;
-      (variable.initializer as ExecutableElementImpl).returnType = newType;
-      if (variable is PropertyInducingElementImpl) {
-        setReturnType(variable.getter, newType);
-        if (!variable.isFinal && !variable.isConst) {
-          setParameterType(variable.setter, newType);
-        }
-      }
+      setFieldType(variable, newType);
     } else {
       // TODO(brianwilkerson) For now we simply don't infer any type for
       // variables or fields involved in a cycle. We could try to be smarter
       // by re-resolving the initializer in a context in which the types of all
       // of the variables in the cycle are assumed to be `null`, but it isn't
       // clear to me that this would produce better results often enough to
       // warrant the extra effort.
     }
     //
     // Record outputs.
@@ skipping 2208 matching lines @@
 
   @override
   bool moveNext() {
     if (_newSources.isEmpty) {
       return false;
     }
     currentTarget = _newSources.removeLast();
     return true;
   }
 }