Fix for 'implemented' notification after an incremental change.

pkg/analyzer/test/generated/incremental_resolver_test.dart

Index: pkg/analyzer/test/generated/incremental_resolver_test.dart
diff --git a/pkg/analyzer/test/generated/incremental_resolver_test.dart b/pkg/analyzer/test/generated/incremental_resolver_test.dart
index 18a45f63bdf4877412ea5f3dfa4d02aad756c255..21b30359d2d7bf403b816f3aefb07c802576b5d4 100644
--- a/pkg/analyzer/test/generated/incremental_resolver_test.dart
+++ b/pkg/analyzer/test/generated/incremental_resolver_test.dart
@@ -4091,6 +4091,28 @@ foo(String p) {}
 ''');
   }
 
+  void test_true_todoHint() {
+    _resolveUnit(r'''
+main() {
+  print(1);
+}
+foo() {
+ // TODO
+}
+''');
+    List<AnalysisError> oldErrors = analysisContext.computeErrors(source);
+    _updateAndValidate(r'''
+main() {
+  print(2);
+}
+foo() {
+ // TODO
+}
+''');
+    List<AnalysisError> newErrors = analysisContext.computeErrors(source);
+    _assertEqualErrors(newErrors, oldErrors);
+  }
+
   void test_true_wholeConstructor() {
     _resolveUnit(r'''
 class A {
@@ -4168,28 +4190,6 @@ class A {
 ''');
   }
 
-  void test_true_todoHint() {
-    _resolveUnit(r'''
-main() {
-  print(1);
-}
-foo() {
- // TODO
-}
-''');
-    List<AnalysisError> oldErrors = analysisContext.computeErrors(source);
-    _updateAndValidate(r'''
-main() {
-  print(2);
-}
-foo() {
- // TODO
-}
-''');
-    List<AnalysisError> newErrors = analysisContext.computeErrors(source);
-    _assertEqualErrors(newErrors, oldErrors);
-  }
-
   void test_unusedHint_add_wasUsedOnlyInPart() {
     Source partSource = addNamedSource(
         '/my_unit.dart',
@@ -4440,6 +4440,36 @@ f3() {
 ''');
   }
 
+  void test_whitespace_getElementAt() {
+    _resolveUnit(r'''
+class A {}
+class B extends A {}
+''');
+    {
+      ClassElement typeA = oldUnitElement.getType('A');
+      expect(oldUnitElement.getElementAt(typeA.nameOffset), typeA);
+    }
+    {
+      ClassElement typeB = oldUnitElement.getType('B');
+      expect(oldUnitElement.getElementAt(typeB.nameOffset), typeB);
+    }
+    _updateAndValidate(r'''
+class A {}
+
+class B extends A {}
+''');
+    // getElementAt() caches results, it should be notificed it when offset
+    // are changed.
+    {
+      ClassElement typeA = oldUnitElement.getType('A');
+      expect(oldUnitElement.getElementAt(typeA.nameOffset), typeA);
+    }
+    {
+      ClassElement typeB = oldUnitElement.getType('B');
+      expect(oldUnitElement.getElementAt(typeB.nameOffset), typeB);
+    }
+  }
+
   void _assertEqualLineInfo(LineInfo incrLineInfo, LineInfo fullLineInfo) {
     for (int offset = 0; offset < 1000; offset++) {
       LineInfo_Location incrLocation = incrLineInfo.getLocation(offset);