dart2js: run dartfmt on tests

tests/compiler/dart2js/sourcemaps/js_tracer.dart

 // Copyright (c) 2016, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 library sourcemap.js_tracer;
 
 import 'package:compiler/src/io/source_information.dart';
 import 'package:compiler/src/io/position_information.dart';
 import 'package:compiler/src/js/js.dart' as js;
 import 'sourcemap_helper.dart';
@@ skipping 64 matching lines @@
         text = ['while(', whileNode.condition, ') ...'];
         break;
       case StepKind.DO_CONDITION:
         js.Do doNode = node;
         text = ['do {... } (', doNode.condition, ')'];
         break;
       case StepKind.SWITCH_EXPRESSION:
         js.Switch switchNode = node;
         text = ['switch(', switchNode.key, ') ...'];
         break;
-
     }
-    createTraceStep(
-        kind,
-        node,
+    createTraceStep(kind, node,
         offset: offset,
-        sourceLocation: getSourceLocation(
-            sourceInformation, sourcePositionKind),
+        sourceLocation:
+            getSourceLocation(sourceInformation, sourcePositionKind),
         text: text);
   }
 
-  void createTraceStep(
-      StepKind kind,
-      js.Node node,
-      {Offset offset,
-       List text,
-       String note,
-       SourceLocation sourceLocation}) {
+  void createTraceStep(StepKind kind, js.Node node,
+      {Offset offset, List text, String note, SourceLocation sourceLocation}) {
     int id = steppableMap.length;
 
     if (text == null) {
       text = [node];
     }
 
-    TraceStep step = new TraceStep(
-        kind,
-        id,
-        node,
-        offset,
-        text,
-        sourceLocation);
+    TraceStep step =
+        new TraceStep(kind, id, node, offset, text, sourceLocation);
     graph.addStep(step);
 
     steppableMap[node] = step;
   }
 
-
   void pushBranch(BranchKind kind, [value]) {
     var branch;
     switch (kind) {
       case BranchKind.CONDITION:
         branch = value ? 't' : 'f';
         break;
       case BranchKind.LOOP:
         branch = 'l';
         break;
       case BranchKind.CATCH:
         branch = 'c';
         break;
       case BranchKind.FINALLY:
         branch = 'F';
         break;
       case BranchKind.CASE:
         branch = '$value';
         break;
     }
     graph.pushBranch(branch);
   }
 
   void popBranch() {
     graph.popBranch();
   }
 }