Improve default support provided for plugins

pkg/analyzer_plugin/test/plugin/plugin_test.dart

Index: pkg/analyzer_plugin/test/plugin/plugin_test.dart
diff --git a/pkg/analyzer_plugin/test/plugin/plugin_test.dart b/pkg/analyzer_plugin/test/plugin/plugin_test.dart
index c460ed4665886ddc90722fde5269824646126e39..3cee9bf50e748c2bef8a03a0e5b5d374605e86b0 100644
--- a/pkg/analyzer_plugin/test/plugin/plugin_test.dart
+++ b/pkg/analyzer_plugin/test/plugin/plugin_test.dart
@@ -82,14 +82,12 @@ class ServerPluginTest {
     expect(plugin.contextRootContaining(filePath2), isNull);
   }
 
-  @failingTest
   void test_handleAnalysisHandleWatchEvents() {
     var result = plugin.handleAnalysisHandleWatchEvents(
         new AnalysisHandleWatchEventsParams([]));
     expect(result, isNotNull);
   }
 
-  @failingTest
   void test_handleAnalysisReanalyze_all() {
     plugin.handleAnalysisSetContextRoots(
         new AnalysisSetContextRootsParams([contextRoot1]));
@@ -254,6 +252,8 @@ class ServerPluginTest {
  * A concrete implementation of a server plugin that is suitable for testing.
  */
 class TestServerPlugin extends ServerPlugin {
+  Map<String, List<AnalysisService>> latestSubscriptions;
+
   TestServerPlugin(ResourceProvider resourceProvider) : super(resourceProvider);
 
   @override
@@ -269,4 +269,10 @@ class TestServerPlugin extends ServerPlugin {
   AnalysisDriverGeneric createAnalysisDriver(ContextRoot contextRoot) {
     return new MockAnalysisDriver();
   }
+
+  @override
+  void sendNotificationsForSubscriptions(
+      Map<String, List<AnalysisService>> subscriptions) {
+    latestSubscriptions = subscriptions;
+  }
 }