Refactor Isolate name format, storage and log

runtime/observatory/tests/service/dev_fs_spawn_test.dart

Index: runtime/observatory/tests/service/dev_fs_spawn_test.dart
diff --git a/runtime/observatory/tests/service/dev_fs_spawn_test.dart b/runtime/observatory/tests/service/dev_fs_spawn_test.dart
index 10b23b01d03b1c2b81f1ce6ec79c562f2690dd68..c2cf90a90a0614694bf04a3691f6ae1235df89da 100644
--- a/runtime/observatory/tests/service/dev_fs_spawn_test.dart
+++ b/runtime/observatory/tests/service/dev_fs_spawn_test.dart
@@ -119,7 +119,7 @@ main(args, msg) {
       if (event.kind == ServiceEvent.kIsolateSpawn) {
         expect(event.spawnToken, equals('mySpawnToken0'));
         expect(event.isolate, isNotNull);
-        expect(event.isolate.name, equals('devfs_file0.dart\$main'));
+        expect(event.isolate.name, equals('devfs_file0.dart:main()'));
         completer.complete(event.isolate);
         sub.cancel();
       }
@@ -147,7 +147,7 @@ main(args, msg) {
       if (event.kind == ServiceEvent.kIsolateSpawn) {
         expect(event.spawnToken, equals('mySpawnToken1'));
         expect(event.isolate, isNotNull);
-        expect(event.isolate.name, equals('devfs_file1.dart\$main'));
+        expect(event.isolate.name, equals('devfs_file1.dart:main()'));
         completer.complete(event.isolate);
         sub.cancel();
       }
@@ -176,7 +176,7 @@ main(args, msg) {
       if (event.kind == ServiceEvent.kIsolateSpawn) {
         expect(event.spawnToken, equals('mySpawnToken2'));
         expect(event.isolate, isNotNull);
-        expect(event.isolate.name, equals('devfs_file2.dart\$main'));
+        expect(event.isolate.name, equals('devfs_file2.dart:main()'));
         completer.complete(event.isolate);
         sub.cancel();
       }