Update final fields inference according to the clarified specification.

pkg/analyzer/test/src/summary/top_level_inference_test.dart

 // Copyright (c) 2017, 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.
 
 import 'dart:async';
 
 import 'package:analyzer/dart/element/element.dart';
 import 'package:analyzer/src/dart/analysis/driver.dart';
 import 'package:test_reflective_loader/test_reflective_loader.dart';
 
@@ skipping 1059 matching lines @@
     checkElementText(
         library,
         r'''
 class A {
   int f;
   A([int this.f]);
 }
 ''');
   }
 
-  test_instanceField_fromAccessors_multiple_different() async {
-    var library = await _encodeDecodeLibrary(r'''
-abstract class A {
-  int get x;
-}
-abstract class B {
-  void set x(String _);
-}
-class C implements A, B {
-  var x;
-}
-''');
-    checkElementText(
-        library,
-        r'''
-abstract class A {
-  int get x;
-}
-abstract class B {
-  void set x(String _);
-}
-class C implements A, B {
-  dynamic x/*error: overrideConflictFieldType*/;
-}
-''');
-  }
-
-  test_instanceField_fromAccessors_multiple_same() async {
-    var library = await _encodeDecodeLibrary(r'''
-abstract class A {
-  int get x;
-}
-abstract class B {
-  void set x(int _);
-}
-class C implements A, B {
-  var x;
-}
-''');
-    checkElementText(
-        library,
-        r'''
-abstract class A {
-  int get x;
-}
-abstract class B {
-  void set x(int _);
-}
-class C implements A, B {
-  int x;
-}
-''');
-  }
-
   test_instanceField_fromField() async {
     var library = await _encodeDecodeLibrary(r'''
 abstract class A {
   int x;
   int y;
   int z;
 }
 class B implements A {
   var x;
   get y => null;
@@ skipping 276 matching lines @@
 }
 abstract class B {
   int get x;
 }
 class C implements A, B {
   int get x {}
 }
 ''');
   }
 
-  test_instanceField_fromGetterSetter_field() async {
+  test_instanceField_fromGetterSetter_different_field() async {
     var library = await _encodeDecodeLibrary(r'''
 abstract class A {
   int get x;
+  int get y;
+}
+abstract class B {
+  void set x(String _);
+  void set y(String _);
+}
+class C implements A, B {
+  var x;
+  final y;
+}
+''');
+    checkElementText(
+        library,
+        r'''
+abstract class A {
+  int get x;
+  int get y;
+}
+abstract class B {
+  void set x(String _);
+  void set y(String _);
+}
+class C implements A, B {
+  dynamic x/*error: overrideConflictFieldType*/;
+  final int y;
+}
+''');
+  }
+
+  test_instanceField_fromGetterSetter_different_getter() async {
+    var library = await _encodeDecodeLibrary(r'''
+abstract class A {
+  int get x;
+}
+abstract class B {
+  void set x(String _);
+}
+class C implements A, B {
+  get x => null;
+}
+''');
+    checkElementText(
+        library,
+        r'''
+abstract class A {
+  synthetic final int x;
+  int get x;
+}
+abstract class B {
+  synthetic String x;
+  void set x(String _);
+}
+class C implements A, B {
+  synthetic final int x;
+  int get x {}
+}
+''',
+        withSyntheticFields: true);
+  }
+
+  test_instanceField_fromGetterSetter_different_setter() async {
+    var library = await _encodeDecodeLibrary(r'''
+abstract class A {
+  int get x;
+}
+abstract class B {
+  void set x(String _);
+}
+class C implements A, B {
+  set x(_);
+}
+''');
+    // TODO(scheglov) test for inference failure error
+    checkElementText(
+        library,
+        r'''
+abstract class A {
+  synthetic final int x;
+  int get x;
+}
+abstract class B {
+  synthetic String x;
+  void set x(String _);
+}
+class C implements A, B {
+  synthetic dynamic x;
+  void set x(dynamic _);
+}
+''',
+        withSyntheticFields: true);
+  }
+
+  test_instanceField_fromGetterSetter_same_field() async {
+    var library = await _encodeDecodeLibrary(r'''
+abstract class A {
+  int get x;
 }
 abstract class B {
   void set x(int _);
 }
 class C implements A, B {
   var x;
 }
 ''');
     checkElementText(
         library,
         r'''
 abstract class A {
   int get x;
 }
 abstract class B {
   void set x(int _);
 }
 class C implements A, B {
   int x;
 }
 ''');
   }
 
-  test_instanceField_fromGetterSetter_getter() async {
+  test_instanceField_fromGetterSetter_same_getter() async {
     var library = await _encodeDecodeLibrary(r'''
 abstract class A {
   int get x;
 }
 abstract class B {
   void set x(int _);
 }
 class C implements A, B {
   get x => null;
 }
@@ skipping 10 matching lines @@
   void set x(int _);
 }
 class C implements A, B {
   synthetic final int x;
   int get x {}
 }
 ''',
         withSyntheticFields: true);
   }
 
-  test_instanceField_fromGetterSetter_setter() async {
+  test_instanceField_fromGetterSetter_same_setter() async {
     var library = await _encodeDecodeLibrary(r'''
 abstract class A {
   int get x;
 }
 abstract class B {
-  void set x(String _);
+  void set x(int _);
 }
 class C implements A, B {
   set x(_);
 }
 ''');
     checkElementText(
         library,
         r'''
 abstract class A {
   synthetic final int x;
   int get x;
 }
 abstract class B {
-  synthetic String x;
-  void set x(String _);
+  synthetic int x;
+  void set x(int _);
 }
 class C implements A, B {
-  synthetic dynamic x;
-  void set x(dynamic _);
+  synthetic int x;
+  void set x(int _);
 }
 ''',
         withSyntheticFields: true);
   }
 
   test_instanceField_fromSetter() async {
     var library = await _encodeDecodeLibrary(r'''
 abstract class A {
   void set x(int _);
   void set y(int _);
@@ skipping 768 matching lines @@
 
   Future<LibraryElement> _encodeDecodeLibrary(String text) async {
     String path = _p('/test.dart');
     provider.newFile(path, text);
     UnitElementResult result = await driver.getUnitElement(path);
     return result.element.library;
   }
 
   String _p(String path) => provider.convertPath(path);
 }