Field property naming fix - issues 14096, 14806

sdk/lib/_internal/compiler/implementation/js_emitter/class_emitter.dart

Index: sdk/lib/_internal/compiler/implementation/js_emitter/class_emitter.dart
diff --git a/sdk/lib/_internal/compiler/implementation/js_emitter/class_emitter.dart b/sdk/lib/_internal/compiler/implementation/js_emitter/class_emitter.dart
index 7035dce72ae65a87d3db91bdda4e4e6a7064ac09..8cc5e3a8e118632e1ef74656f15ecaf26c6aa5be 100644
--- a/sdk/lib/_internal/compiler/implementation/js_emitter/class_emitter.dart
+++ b/sdk/lib/_internal/compiler/implementation/js_emitter/class_emitter.dart
@@ -160,8 +160,6 @@ class ClassEmitter extends CodeEmitterHelper {
             buffer.write(accessorName);
             if (name != accessorName) {
               buffer.write(':$name');
-              // Only the native classes can have renaming accessors.
-              assert(classIsNative);
             }
 
             int getterCode = 0;
@@ -423,26 +421,16 @@ class ClassEmitter extends CodeEmitterHelper {
       // setters.
       bool needsGetter = false;
       bool needsSetter = false;
-      // We need to name shadowed fields differently, so they don't clash with
-      // the non-shadowed field.
-      bool isShadowed = false;
       if (isLibrary || isMixinNativeField || holder == element) {
         needsGetter = fieldNeedsGetter(field);
         needsSetter = fieldNeedsSetter(field);
-      } else {
-        ClassElement cls = element;
-        isShadowed = cls.isShadowedByField(field);
       }
 
       if ((isInstantiated && !holder.isNative())
           || needsGetter
           || needsSetter) {
-        String accessorName = isShadowed
-            ? namer.shadowedFieldName(field)
-            : namer.getNameOfField(field);
-        String fieldName = field.hasFixedBackendName()
-            ? field.fixedBackendName()
-            : (isMixinNativeField ? name : accessorName);
+        String accessorName = namer.fieldAccessorName(field);
+        String fieldName = namer.fieldPropertyName(field);
         bool needsCheckedSetter = false;
         if (compiler.enableTypeAssertions
             && needsSetter