Fix incremental parsing of import combinators.

pkg/analyzer/test/generated/parser_test.dart

Index: pkg/analyzer/test/generated/parser_test.dart
diff --git a/pkg/analyzer/test/generated/parser_test.dart b/pkg/analyzer/test/generated/parser_test.dart
index 7ee8a2c21c7a2b2fa633f0944227f5601461722b..1dc7170cf7a1f27ba5683bb228cfa014d5fd2aab 100644
--- a/pkg/analyzer/test/generated/parser_test.dart
+++ b/pkg/analyzer/test/generated/parser_test.dart
@@ -2604,6 +2604,10 @@ class IncrementalParserTest extends EngineTestCase {
     _assertParse('class C { void f(', '', 'arg', ') {} }');
   }
 
+  void test_insert_identifier_inCombinator() {
+    _assertParse("import 'foo.dart' show x", "", ", y", ";");
+  }
+
   void test_insert_insideClassBody() {
     // "class C {C(); }"
     // "class C { C(); }"
@@ -6503,6 +6507,22 @@ class SimpleParserTest extends ParserTestCase {
     expect(classTypeAlias.semicolon, isNotNull);
   }
 
+  void test_parseCombinator_hide() {
+    HideCombinator combinator =
+        ParserTestCase.parse4('parseCombinator', 'hide a;');
+    expect(combinator, new isInstanceOf<HideCombinator>());
+    expect(combinator.keyword, isNotNull);
+    expect(combinator.hiddenNames, hasLength(1));
+  }
+
+  void test_parseCombinator_show() {
+    ShowCombinator combinator =
+        ParserTestCase.parse4('parseCombinator', 'show a;');
+    expect(combinator, new isInstanceOf<ShowCombinator>());
+    expect(combinator.keyword, isNotNull);
+    expect(combinator.shownNames, hasLength(1));
+  }
+
   void test_parseCombinators_h() {
     List<Combinator> combinators =
         ParserTestCase.parse4("parseCombinators", "hide a;");