Encode super calls via extra properties on prototypes.

sdk/lib/_internal/compiler/implementation/js_emitter/old_emitter/emitter.dart

Index: sdk/lib/_internal/compiler/implementation/js_emitter/old_emitter/emitter.dart
diff --git a/sdk/lib/_internal/compiler/implementation/js_emitter/old_emitter/emitter.dart b/sdk/lib/_internal/compiler/implementation/js_emitter/old_emitter/emitter.dart
index 6c266153502120b97a67edcb207ad9877eaddfc2..1f7f2f5bcaacf40f99540200e3d89230b541160e 100644
--- a/sdk/lib/_internal/compiler/implementation/js_emitter/old_emitter/emitter.dart
+++ b/sdk/lib/_internal/compiler/implementation/js_emitter/old_emitter/emitter.dart
@@ -308,9 +308,15 @@ class OldEmitter implements Emitter {
         var inheritFrom = function() {
           function tmp() {}
           var hasOwnProperty = Object.prototype.hasOwnProperty;
-          return function (constructor, superConstructor) {
+          return function (constructor, superConstructor, aliases) {
             tmp.prototype = superConstructor.prototype;
             var object = new tmp();
+            if (aliases) {
+              for (var pos = 0; pos < aliases.length; pos++) {
+                var member = aliases[pos].split(':');
+                object[member[0]] = object[member[1]];
+              }
+            }
             var properties = constructor.prototype;
             for (var member in properties)
               if (hasOwnProperty.call(properties, member))
@@ -350,6 +356,7 @@ class OldEmitter implements Emitter {
     return js('''
       function(collectedClasses, isolateProperties, existingIsolateProperties) {
         var pendingClasses = Object.create(null);
+        var pendingAliases = Object.create(null);
         if (!#) # = Object.create(null);  // embedded allClasses.
         var allClasses = #;  // embedded allClasses;
 
@@ -373,16 +380,17 @@ class OldEmitter implements Emitter {
           if (desc instanceof Array) desc = desc[1];
 
           /* The 'fields' are either a constructor function or a
-           * string encoding fields, constructor and superclass.  Get
-           * the superclass and the fields in the format
-           *   '[name/]Super;field1,field2'
+           * string encoding fields, constructor, superclass and methods from
+           * the superclass that need aliasing.  Get the superclass, fields 
+           * and aliases in the format
+           *   '[name/]Super;field1,field2;alias,alias2'
            * from the CLASS_DESCRIPTOR_PROPERTY property on the descriptor.
            * The 'name/' is optional and contains the name that should be used
            * when printing the runtime type string.  It is used, for example,
            * to print the runtime type JSInt as 'int'.
            */
           var classData = desc["${namer.classDescriptorProperty}"],
-              supr, name = cls, fields = classData;
+              supr, name = cls, fields = classData, aliases = false;
           if (#)  // backend.hasRetainedMetadata
             if (typeof classData == "object" &&
                 classData instanceof Array) {
@@ -398,7 +406,9 @@ class OldEmitter implements Emitter {
 
           var s = fields.split(";");
           fields = s[1] == "" ? [] : s[1].split(",");
+          if (s.length == 3) aliases = s[2].split(",");
           supr = s[0];
+
           split = supr.split(":");
           if (split.length == 2) {
             supr = split[0];
@@ -427,6 +437,7 @@ class OldEmitter implements Emitter {
             constructorsList.push(cls);
           }
           if (supr) pendingClasses[cls] = supr;
+          if (aliases) pendingAliases[cls] = aliases;
         }
 
         if (typeof dart_precompiled != "function") {
@@ -497,6 +508,7 @@ class OldEmitter implements Emitter {
         finishedClasses[cls] = true;
 
         var superclass = pendingClasses[cls];
+        var aliases = pendingAliases[cls];
 
         // The superclass is only false (empty string) for the Dart Object
         // class.  The minifier together with noSuchMethod can put methods on
@@ -510,7 +522,7 @@ class OldEmitter implements Emitter {
         if (!superConstructor)
           superConstructor = existingIsolateProperties[superclass];
 
-        var prototype = inheritFrom(constructor, superConstructor);
+        var prototype = inheritFrom(constructor, superConstructor, aliases);
 
         if (#) {  // !nativeClasses.isEmpty,
           // The property looks like this: