dart2js: run dartfmt on tests

tests/compiler/dart2js/deferred_load_mapping_test.dart

Index: tests/compiler/dart2js/deferred_load_mapping_test.dart
diff --git a/tests/compiler/dart2js/deferred_load_mapping_test.dart b/tests/compiler/dart2js/deferred_load_mapping_test.dart
index 34ba2e8abe7b7d36126beeb9996910d56a6ce2ac..18be4f0103eba5c8ad718fe8efcab355b00ccde4 100644
--- a/tests/compiler/dart2js/deferred_load_mapping_test.dart
+++ b/tests/compiler/dart2js/deferred_load_mapping_test.dart
@@ -16,8 +16,7 @@ void main() {
         outputProvider: collector);
     CompilerImpl compiler = result.compiler;
     // Ensure a mapping file is output.
-    Expect.isNotNull(
-        collector.getOutput("deferred_map.json", "deferred_map"));
+    Expect.isNotNull(collector.getOutput("deferred_map.json", "deferred_map"));
 
     Map mapping = compiler.deferredLoadTask.computeDeferredMap();
     // Test structure of mapping.
@@ -32,7 +31,7 @@ void main() {
 }
 
 const Map MEMORY_SOURCE_FILES = const {
-  "main.dart":"""
+  "main.dart": """
 import 'dart:convert' deferred as convert;
 import 'lib1.dart' deferred as lib1;
 import 'lib2.dart' deferred as lib2;
@@ -50,7 +49,7 @@ void main() {
   });
 }
 """,
-  "lib1.dart":"""
+  "lib1.dart": """
 library lib1;
 import "dart:async";
 import "dart:html";
@@ -68,7 +67,7 @@ foo1() {
   return () {return 1 + l3.foo3();} ();
 }
 """,
-  "lib2.dart":"""
+  "lib2.dart": """
 library lib2;
 import "dart:async";
 import "lib3.dart" as l3;
@@ -81,14 +80,14 @@ foo2() {
   return () {return 2+l3.foo3();} ();
 }
 """,
-  "lib3.dart":"""
+  "lib3.dart": """
 library lib3;
 
 foo3() {
   return () {return 3;} ();
 }
 """,
-  "lib4.dart":"""
+  "lib4.dart": """
 library lib4;
 
 bar1() {