Replace ResultProvider with 'aboutToComputeResult'.

pkg/analyzer/test/generated/engine_test.dart

Index: pkg/analyzer/test/generated/engine_test.dart
diff --git a/pkg/analyzer/test/generated/engine_test.dart b/pkg/analyzer/test/generated/engine_test.dart
index a404b92c6b6a3627ac0a9465db4a3e91f9792ad3..e2b20b39a149bc45e63753eede254d3f6c79c632 100644
--- a/pkg/analyzer/test/generated/engine_test.dart
+++ b/pkg/analyzer/test/generated/engine_test.dart
@@ -348,6 +348,12 @@ class TestAnalysisContext implements InternalAnalysisContext {
   }
 
   @override
+  bool aboutToComputeResult(CacheEntry entry, ResultDescriptor result) {
+    fail("Unexpected invocation of aboutToComputeResult");
+    return false;
+  }
+
+  @override
   void addListener(AnalysisListener listener) {
     fail("Unexpected invocation of addListener");
   }