Extract PerformanceLogger from AnalysisDriver.

pkg/analysis_server/lib/src/analysis_server.dart

Index: pkg/analysis_server/lib/src/analysis_server.dart
diff --git a/pkg/analysis_server/lib/src/analysis_server.dart b/pkg/analysis_server/lib/src/analysis_server.dart
index 1ea8817e47ce181dd095c1f649c49cb980e43694..cc95b58ee221bee9cbc94209559f9d5a5a191fcc 100644
--- a/pkg/analysis_server/lib/src/analysis_server.dart
+++ b/pkg/analysis_server/lib/src/analysis_server.dart
@@ -67,6 +67,7 @@ import 'package:analyzer/src/generated/utilities_general.dart';
 import 'package:analyzer/src/task/dart.dart';
 import 'package:analyzer/src/util/glob.dart';
 import 'package:analyzer/task/dart.dart';
+import 'package:front_end/src/base/performace_logger.dart' as nd;

[Brian Wilkerson, 2017/05/12 21:16:09]

Does this really need to be prefixed? If so, does 'nd' mean something? If not,
could we choose an identifier that does?

[scheglov, 2017/05/12 21:27:55]

"nd" means "new driver" :-)
I had to use it to avoid conflicts between AnalysisDriver classes.
We might try to get rid of it altogether.
Definitely can do this for PerformanceLogger.
Fixed.

 import 'package:front_end/src/incremental/byte_store.dart';
 import 'package:front_end/src/incremental/file_byte_store.dart';
 import 'package:plugin/plugin.dart';