Use AnalysisDriver.getCachedResult() for 'implemented' notification.

pkg/analysis_server/test/analysis_abstract.dart

Index: pkg/analysis_server/test/analysis_abstract.dart
diff --git a/pkg/analysis_server/test/analysis_abstract.dart b/pkg/analysis_server/test/analysis_abstract.dart
index 5723548aa247da9462d0fafd6ab46bf90e3d8dde..c37be8f20d272e892883ca27c2c7f6a13bb06019 100644
--- a/pkg/analysis_server/test/analysis_abstract.dart
+++ b/pkg/analysis_server/test/analysis_abstract.dart
@@ -212,6 +212,11 @@ class AbstractAnalysisTest {
     handleSuccessfulRequest(request);
   }
 
+  void setPriorityFiles(List<String> files) {
+    var request = new AnalysisSetPriorityFilesParams(files).toRequest('0');
+    handleSuccessfulRequest(request);
+  }
+
   void setUp() {
     serverChannel = new MockServerChannel();
     resourceProvider = new MemoryResourceProvider();