Revert "Construct literal maps using factory constructor."

sdk/lib/_internal/compiler/implementation/js_backend/backend.dart

Index: sdk/lib/_internal/compiler/implementation/js_backend/backend.dart
diff --git a/sdk/lib/_internal/compiler/implementation/js_backend/backend.dart b/sdk/lib/_internal/compiler/implementation/js_backend/backend.dart
index cf6c61c0fadcb3e4df52d549651af7973ef94f5a..64d62e5ddb59080d42670c5b33adced238e82dfa 100644
--- a/sdk/lib/_internal/compiler/implementation/js_backend/backend.dart
+++ b/sdk/lib/_internal/compiler/implementation/js_backend/backend.dart
@@ -102,8 +102,6 @@ class JavaScriptBackend extends Backend {
   ClassElement mapLiteralClass;
   ClassElement constMapLiteralClass;
   ClassElement typeVariableClass;
-  Element mapLiteralConstructor;
-  Element mapLiteralConstructorEmpty;
 
   ClassElement noSideEffectsClass;
   ClassElement noThrowsClass;
@@ -730,6 +728,7 @@ class JavaScriptBackend extends Backend {
         // For map literals, the dependency between the implementation class
         // and [Map] is not visible, so we have to add it manually.
         rti.registerRtiDependency(mapLiteralClass, cls);
+        enqueueInResolution(getMapMaker(), elements);
       } else if (cls == compiler.boundClosureClass) {
         // TODO(ngeoffray): Move the bound closure class in the
         // backend.
@@ -738,24 +737,6 @@ class JavaScriptBackend extends Backend {
         enqueue(enqueuer, getNativeInterceptorMethod, elements);
         enqueueClass(enqueuer, jsInterceptorClass, compiler.globalDependencies);
         enqueueClass(enqueuer, jsPlainJavaScriptObjectClass, elements);
-      } else if (cls == mapLiteralClass) {
-        // For map literals, the dependency between the implementation class
-        // and [Map] is not visible, so we have to add it manually.
-        Element getFactory(String name, int arity) {
-          return mapLiteralClass.patch.lookupConstructor(
-            new Selector.callConstructor(
-                name, mapLiteralClass.getLibrary(), arity),
-            (element) {
-              compiler.internalError(mapLiteralClass,
-                  "Map literal class $mapLiteralClass missing "
-                  "'$name' constructor"
-                  "  ${mapLiteralClass.constructors}");
-            });
-        }
-        mapLiteralConstructor = getFactory('_literal', 1);
-        mapLiteralConstructorEmpty = getFactory('_empty', 0);
-        enqueueInResolution(mapLiteralConstructor, elements);
-        enqueueInResolution(mapLiteralConstructorEmpty, elements);
       }
     }
     if (cls == compiler.closureClass) {
@@ -1467,6 +1448,10 @@ class JavaScriptBackend extends Backend {
     return compiler.findHelper('getTraceFromException');
   }
 
+  Element getMapMaker() {
+    return compiler.findHelper('makeLiteralMap');
+  }
+
   Element getSetRuntimeTypeInfo() {
     return compiler.findHelper('setRuntimeTypeInfo');
   }
@@ -1901,3 +1886,4 @@ class Dependency {
 
   const Dependency(this.constant, this.user);
 }
+