dart2js: patch file support cleanup

pkg/compiler/lib/src/compiler.dart

Index: pkg/compiler/lib/src/compiler.dart
diff --git a/pkg/compiler/lib/src/compiler.dart b/pkg/compiler/lib/src/compiler.dart
index 67c4e599583b097f982e000f18d9dcc0501bb249..f8e88ebb3020b5fb3b318348b62b8a96d357a99f 100644
--- a/pkg/compiler/lib/src/compiler.dart
+++ b/pkg/compiler/lib/src/compiler.dart
@@ -425,10 +425,6 @@ abstract class Compiler {
     return loadedLibraries;
   }
 
-  // TODO(johnniwinther): Move this to [PatchParser] when it is moved to the
-  // [JavaScriptBackend]. Currently needed for testing.
-  String get patchVersion => backend.patchVersion;
-
   /**
    * Get an [Uri] pointing to a patch for the dart: library with
    * the given path. Returns null if there is no patch.