Reapply "Add support for generic function type syntax, part 1"

pkg/analyzer/tool/summary/generate.dart

Index: pkg/analyzer/tool/summary/generate.dart
diff --git a/pkg/analyzer/tool/summary/generate.dart b/pkg/analyzer/tool/summary/generate.dart
index d3fd86372118f1a537ee09e71d8f2b0e9be5a735..6db5cf034681b335e6aa06cd4c06e672cc21ddd3 100644
--- a/pkg/analyzer/tool/summary/generate.dart
+++ b/pkg/analyzer/tool/summary/generate.dart
@@ -268,10 +268,13 @@ class _CodeGenerator {
         for (ClassMember classMember in decl.members) {
           if (classMember is MethodDeclaration && classMember.isGetter) {
             String desc = '$clsName.${classMember.name.name}';
-            TypeName type = classMember.returnType;
-            if (type == null) {
-              throw new Exception('Class member needs a type: $desc');
+            if (classMember.returnType is! TypeName) {
+              if (classMember.returnType == null) {
+                throw new Exception('Class member needs a type: $desc');
+              }
+              throw new Exception('Class member needs a class type: $desc');
             }
+            TypeName type = classMember.returnType;
             bool isList = false;
             if (type.name.name == 'List' &&
                 type.typeArguments != null &&