Send 'analysis.flushResults' on file removal.

pkg/analysis_server/test/context_manager_test.dart

Index: pkg/analysis_server/test/context_manager_test.dart
diff --git a/pkg/analysis_server/test/context_manager_test.dart b/pkg/analysis_server/test/context_manager_test.dart
index 46a2d44dd3a70f4f6c09f361b0936fe26a27746d..c95252b21a13f7905bbdd925d1e7d1ec09281b44 100644
--- a/pkg/analysis_server/test/context_manager_test.dart
+++ b/pkg/analysis_server/test/context_manager_test.dart
@@ -2521,6 +2521,11 @@ class TestContextManagerCallbacks extends ContextManagerCallbacks {
     currentContext.applyChanges(changeSet);
   }
 
+  @override
+  void applyFileRemoved(AnalysisDriver driver, String file) {
+    throw new StateError('Unexpected invocation of applyFileRemoved');
+  }
+
   void assertContextFiles(String contextPath, List<String> expectedFiles) {
     var actualFiles = currentContextFilePaths[contextPath].keys;
     expect(actualFiles, unorderedEquals(expectedFiles));