Stop propagating return types for top-level function declarations

R=paulberry@google.com, scheglov@google.com

Review URL: https://codereview.chromium.org//1309243007 .

pkg/analyzer/lib/src/generated/static_type_analyzer.dart

@@ -328,7 +328,9 @@ class StaticTypeAnalyzer extends SimpleAstVisitor<Object> {
         node.element as ExecutableElementImpl;
     functionElement.returnType =
         _computeStaticReturnTypeOfFunctionDeclaration(node);
-    _recordPropagatedTypeOfFunction(functionElement, function.body);
+    if (node.parent is FunctionDeclarationStatement) {
+      _recordPropagatedTypeOfFunction(functionElement, function.body);
+    }
     _recordStaticType(function, functionElement.type);
     return null;
   }

pkg/analyzer/test/generated/incremental_resolver_test.dart

@@ -2346,6 +2346,41 @@ class A {
 ''');
   }
 
+  void test_true_functionExpression() {
+    _assertMatches(r'''
+import 'dart:async';
+
+class A {
+  Future<int> mmm() async {
+    return 42;
+  }
+
+  a() {
+    mmm().then((p1) {
+      return p1.toString();
+    }).then((p2) {
+      print(p2);
+    });
+  }
+}
+''', r'''import 'dart:async';
+
+class A {
+  Future<int> mmm() async {
+    return 42;
+  }
+
+  a() {
+    mmm().then((int p1) {
+      return p1.toString();
+    }).then((String p2) {
+      print(p2);
+    });
+  }
+}
+''');
+  }
+
   void test_true_functionTypeAlias_list_reorder() {
     _assertMatches(
         r'''

pkg/analyzer/test/generated/resolver_test.dart

@@ -13443,72 +13443,6 @@ f1(x) {
         typeProvider.stringType);
   }
 
-  void test_propagatedReturnType_function_hasReturnType_returnsNull() {
-    String code = r'''
-String f() => null;
-main() {
-  var v = f();
-}''';
-    _assertPropagatedAssignedType(
-        code, typeProvider.dynamicType, typeProvider.stringType);
-  }
-
-  void test_propagatedReturnType_function_lessSpecificStaticReturnType() {
-    String code = r'''
-Object f() => 42;
-main() {
-  var v = f();
-}''';
-    _assertPropagatedAssignedType(
-        code, typeProvider.dynamicType, typeProvider.intType);
-  }
-
-  void test_propagatedReturnType_function_moreSpecificStaticReturnType() {
-    String code = r'''
-int f(v) => (v as num);
-main() {
-  var v = f(3);
-}''';
-    _assertPropagatedAssignedType(
-        code, typeProvider.dynamicType, typeProvider.intType);
-  }
-
-  void test_propagatedReturnType_function_noReturnTypeName_blockBody_multipleReturns() {
-    String code = r'''
-f() {
-  if (true) return 0;
-  return 1.0;
-}
-main() {
-  var v = f();
-}''';
-    _assertPropagatedAssignedType(
-        code, typeProvider.dynamicType, typeProvider.numType);
-  }
-
-  void test_propagatedReturnType_function_noReturnTypeName_blockBody_oneReturn() {
-    String code = r'''
-f() {
-  var z = 42;
-  return z;
-}
-main() {
-  var v = f();
-}''';
-    _assertPropagatedAssignedType(
-        code, typeProvider.dynamicType, typeProvider.intType);
-  }
-
-  void test_propagatedReturnType_function_noReturnTypeName_expressionBody() {
-    String code = r'''
-f() => 42;
-main() {
-  var v = f();
-}''';
-    _assertPropagatedAssignedType(
-        code, typeProvider.dynamicType, typeProvider.intType);
-  }
-
   void test_propagatedReturnType_localFunction() {
     String code = r'''
 main() {