issue 4817 fixed. Implemented raw strings with 'r' instead of '@' for dart2js

tests/compiler/dart2js/return_type_inferer_test.dart

Index: tests/compiler/dart2js/return_type_inferer_test.dart
diff --git a/tests/compiler/dart2js/return_type_inferer_test.dart b/tests/compiler/dart2js/return_type_inferer_test.dart
index c485c19525f41ad46ccd6630580e9ce5abfc1627..43ef1386374dc7494ca0f6926892874c14e3ef77 100644
--- a/tests/compiler/dart2js/return_type_inferer_test.dart
+++ b/tests/compiler/dart2js/return_type_inferer_test.dart
@@ -6,42 +6,42 @@
 
 #import('compiler_helper.dart');
 
-const String TEST_ONE = @"""
+const String TEST_ONE = r"""
   f(p) { if (p == null) return p; else return p; }
   main() { f("s"); }
 """;
 
-const String TEST_TWO = @"""
+const String TEST_TWO = r"""
   f(p) { if (p == null) return p; else return p; }
   main() { f(1); }
 """;
 
-const String TEST_THREE = @"""
+const String TEST_THREE = r"""
   f(p) { if (p == null) return p; else return p; }
   main() { f(1); f(2); }
 """;
 
-const String TEST_FOUR = @"""
+const String TEST_FOUR = r"""
   f(p) { if (p == null) return p; else return p; }
   main() { f(1.1); }
 """;
 
-const String TEST_FIVE = @"""
+const String TEST_FIVE = r"""
   f(p) { if (p == null) return p; else return p; }
   main() { f(1); f(2.2); }
 """;
 
-const String TEST_SIX = @"""
+const String TEST_SIX = r"""
   f(p) { if (p == null) return p; else return p; }
   main() { f(1.1); f(2); }
 """;
 
-const String TEST_SEVEN = @"""
+const String TEST_SEVEN = r"""
   f(p) { if (p == null) return p; else return p; }
   main() { f(1); f("s"); }
 """;
 
-const String TEST_EIGHT = @"""
+const String TEST_EIGHT = r"""
   f(p1, p2) {
     if (p1 == null) return p1;
     else return p1;
@@ -49,7 +49,7 @@ const String TEST_EIGHT = @"""
   main() { f(1, 2); f(1, "s"); }
 """;
 
-const String TEST_NINE = @"""
+const String TEST_NINE = r"""
   f(p1, p2) {
     if (p1 == null) return p1;
     else return p1;
@@ -57,7 +57,7 @@ const String TEST_NINE = @"""
   main() { f("s", 2); f(1, "s"); }
 """;
 
-const String TEST_TEN = @"""
+const String TEST_TEN = r"""
   f(p) { if (p == null) return p; else return p; }
   g(p) { if (p == null) return p; else return p; }
   main() { f(1); g(f); }