Deal with the JS helper separately from the 'native' keyword.

lib/compiler/implementation/patch_parser.dart

Index: lib/compiler/implementation/patch_parser.dart
diff --git a/lib/compiler/implementation/patch_parser.dart b/lib/compiler/implementation/patch_parser.dart
index 4ea29b45cbeef6b9e44b3472f1f9bf186d2ef70c..35a0654dd07a8cc4d9df9804659b40460522d95e 100644
--- a/lib/compiler/implementation/patch_parser.dart
+++ b/lib/compiler/implementation/patch_parser.dart
@@ -30,7 +30,7 @@ class PatchParserTask extends leg.CompilerTask {
     compiler.withCurrentElement(compilationUnit, () {
       // This patches the elements of the patch library into [library].
       // Injected elements are added directly under the compilation unit.
-      // Patche elements are stored on the patched functions or classes.
+      // Patch elements are stored on the patched functions or classes.
       scanLibraryElements(compilationUnit, imports);
     });
     // After scanning declarations, we handle the import tags in the patch.