Clean up some code in plugins

pkg/analyzer_plugin/lib/src/channel/isolate_channel.dart

Index: pkg/analyzer_plugin/lib/src/channel/isolate_channel.dart
diff --git a/pkg/analyzer_plugin/lib/src/channel/isolate_channel.dart b/pkg/analyzer_plugin/lib/src/channel/isolate_channel.dart
index e712d08b25d380eb81ed219ccd7b6bcbcdff9ee7..3b90b51e4c9425947016d09baabae300dde31d56 100644
--- a/pkg/analyzer_plugin/lib/src/channel/isolate_channel.dart
+++ b/pkg/analyzer_plugin/lib/src/channel/isolate_channel.dart
@@ -121,7 +121,6 @@ class PluginIsolateChannel implements PluginCommunicationChannel {
       {Function onError, void onDone()}) {
     void onData(data) {
       Map<String, Object> requestMap = data;
-//      print('[plugin] Received request: ${JSON.encode(requestMap)}');
       Request request = new Request.fromJson(requestMap);
       if (request != null) {
         onRequest(request);
@@ -138,14 +137,12 @@ class PluginIsolateChannel implements PluginCommunicationChannel {
   @override
   void sendNotification(Notification notification) {
     Map<String, Object> json = notification.toJson();
-//    print('[plugin] Send notification: ${JSON.encode(json)}');
     _sendPort.send(json);
   }
 
   @override
   void sendResponse(Response response) {
     Map<String, Object> json = response.toJson();
-//    print('[plugin] Send response: ${JSON.encode(json)}');
     _sendPort.send(json);
   }
 }