addFile() must refresh the file.

pkg/analyzer/lib/src/dart/analysis/driver.dart

Index: pkg/analyzer/lib/src/dart/analysis/driver.dart
diff --git a/pkg/analyzer/lib/src/dart/analysis/driver.dart b/pkg/analyzer/lib/src/dart/analysis/driver.dart
index 54c526ec1f63a8f1b03779068ea39d16d236ec4a..b08cfac0753af81bb94b6f4f878916d31ff075e3 100644
--- a/pkg/analyzer/lib/src/dart/analysis/driver.dart
+++ b/pkg/analyzer/lib/src/dart/analysis/driver.dart
@@ -384,6 +384,7 @@ class AnalysisDriver {
   void addFile(String path) {
     if (AnalysisEngine.isDartFileName(path)) {
       _explicitFiles.add(path);
+      _changedFiles.add(path);
       _filesToAnalyze.add(path);
     }
     _statusSupport.transitionToAnalyzing();