Use an enum in embedded_names as input to JS_GET_NAME.

pkg/compiler/lib/src/js_backend/backend.dart

Index: pkg/compiler/lib/src/js_backend/backend.dart
diff --git a/pkg/compiler/lib/src/js_backend/backend.dart b/pkg/compiler/lib/src/js_backend/backend.dart
index 75f3dab49e198e7a3d9bf2656793766d72e2e1c4..da276e4ddf9f576ffa39ea7997f6ebcd03500571 100644
--- a/pkg/compiler/lib/src/js_backend/backend.dart
+++ b/pkg/compiler/lib/src/js_backend/backend.dart
@@ -73,6 +73,8 @@ class JavaScriptBackend extends Backend {
       new Uri(scheme: 'dart', path: '_js_mirrors');
   static final Uri DART_JS_NAMES =
       new Uri(scheme: 'dart', path: '_js_names');
+  static final Uri DART_EMBEDDED_NAMES =
+      new Uri(scheme: 'dart', path: '_js_embedded_names');
   static final Uri DART_ISOLATE_HELPER =
       new Uri(scheme: 'dart', path: '_isolate_helper');
   static final Uri DART_HTML =
@@ -364,6 +366,9 @@ class JavaScriptBackend extends Backend {
   /// Holds the method "requiresPreamble" in _js_helper.
   FunctionElement requiresPreambleMarker;
 
+  /// Holds the class for the [JsGetName] enum.
+  EnumClassElement jsGetNameEnum;
+
   /// True if a call to preserveMetadataMarker has been seen.  This means that
   /// metadata must be retained for dart:mirrors to work correctly.
   bool mustRetainMetadata = false;
@@ -1876,6 +1881,8 @@ class JavaScriptBackend extends Backend {
         preserveLibraryNamesMarker = find(library, 'preserveLibraryNames');
       } else if (uri == DART_JS_NAMES) {
         preserveNamesMarker = find(library, 'preserveNames');
+      } else if (uri == DART_EMBEDDED_NAMES) {
+        jsGetNameEnum = find(library, 'JsGetName');
       } else if (uri == DART_HTML) {
         htmlLibraryIsLoaded = true;
       }