Fix issue 7086: support call-through getter for interceptor classes.

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

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 part of js_backend;
 
 /**
  * A function element that represents a closure call. The signature is copied
  * from the given element.
  */
@@ skipping 1286 matching lines @@
   /**
    * Documentation wanted -- johnniwinther
    *
    * Invariant: [member] must be a declaration element.
    */
   void emitCallStubForGetter(Element member,
                              Set<Selector> selectors,
                              DefineMemberFunction defineInstanceMember) {
     assert(invariant(member, member.isDeclaration));
     LibraryElement memberLibrary = member.getLibrary();
+    JavaScriptBackend backend = compiler.backend;
+    // If the class is an interceptor class, the stub gets the
+    // receiver explicitely and we need to pass it to the getter call.
+    bool isInterceptorClass =
+        backend.isInterceptorClass(member.getEnclosingClass());
+    String extraArgument = isInterceptorClass ? 'receiver' : '';
     String getter;
     if (member.isGetter()) {
-      getter = "this.${namer.getterName(member.getLibrary(), member.name)}()";
+      String getterName = namer.getterName(member.getLibrary(), member.name);
+      getter = "this.$getterName($extraArgument)";
     } else {
       String name = member.isNative()
           ? member.nativeName()
           : namer.instanceFieldName(memberLibrary, member.name);
       getter = "this.$name";
     }
+
     for (Selector selector in selectors) {
       if (selector.applies(member, compiler)) {
         String invocationName =
             namer.instanceMethodInvocationName(memberLibrary, member.name,
                                                selector);
         SourceString callName = Namer.CLOSURE_INVOCATION_NAME;
         String closureCallName =
             namer.instanceMethodInvocationName(memberLibrary, callName,
                                                selector);
         List<String> arguments = <String>[];
         for (int i = 0; i < selector.argumentCount; i++) {
           arguments.add("arg$i");
         }
         String joined = Strings.join(arguments, ", ");
         CodeBuffer getterBuffer = new CodeBuffer();
+        getterBuffer.add("function(");
+        if (isInterceptorClass) {
+          getterBuffer.add(extraArgument);
+          if (!arguments.isEmpty) {
+            getterBuffer.add(', ');
+          }
+        }
         getterBuffer.add(
-            "function($joined) { return $getter.$closureCallName($joined); }");
+            "$joined) { return $getter.$closureCallName($joined); }");
         defineInstanceMember(invocationName, getterBuffer);
       }
     }
   }
 
   void emitStaticNonFinalFieldInitializations(CodeBuffer buffer) {
     ConstantHandler handler = compiler.constantHandler;
     List<VariableElement> staticNonFinalFields =
         handler.getStaticNonFinalFieldsForEmission();
     for (Element element in staticNonFinalFields) {
@@ skipping 489 matching lines @@
 const String HOOKS_API_USAGE = """
 // Generated by dart2js, the Dart to JavaScript compiler.
 // The code supports the following hooks:
 // dartPrint(message)   - if this function is defined it is called
 //                        instead of the Dart [print] method.
 // dartMainRunner(main) - if this function is defined, the Dart [main]
 //                        method will not be invoked directly.
 //                        Instead, a closure that will invoke [main] is
 //                        passed to [dartMainRunner].
 """;