[Object.observe] Implement implicit notification from performChange

test/mjsunit/harmony/object-observe.js

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 416 matching lines @@
 Thingy.INCREMENT_AND_MULTIPLY = 'incrementAndMultiply';
 
 Thingy.prototype = {
   increment: function(amount) {
     var notifier = Object.getNotifier(this);
 
     var self = this;
     notifier.performChange(Thingy.INCREMENT, function() {
       self.a += amount;
       self.b += amount;
-    });
 
-    notifier.notify({
-      object: this,
-      type: Thingy.INCREMENT,
-      incremented: amount
+      return {
+        incremented: amount
+      };  // implicit notify
     });
   },
 
   multiply: function(amount) {
     var notifier = Object.getNotifier(this);
 
     var self = this;
     notifier.performChange(Thingy.MULTIPLY, function() {
       self.a *= amount;
       self.b *= amount;
-    });
 
-    notifier.notify({
-      object: this,
-      type: Thingy.MULTIPLY,
-      multiplied: amount
+      return {
+        multiplied: amount
+      };  // implicit notify
     });
   },
 
   incrementAndMultiply: function(incAmount, multAmount) {
     var notifier = Object.getNotifier(this);
 
     var self = this;
     notifier.performChange(Thingy.INCREMENT_AND_MULTIPLY, function() {
       self.increment(incAmount);
       self.multiply(multAmount);
-    });
 
-    notifier.notify({
-      object: this,
-      type: Thingy.INCREMENT_AND_MULTIPLY,
-      incremented: incAmount,
-      multiplied: multAmount
+      return {
+        incremented: incAmount,
+        multiplied: multAmount
+      };  // implicit notify
     });
   }
 }
 
 Thingy.observe = function(thingy, callback) {
   Object.observe(thingy, callback, [Thingy.INCREMENT,
                                     Thingy.MULTIPLY,
                                     Thingy.INCREMENT_AND_MULTIPLY,
                                     'updated']);
 }
@@ skipping 52 matching lines @@
     if (!n)
       return;
     var notifier = Object.getNotifier(this);
     var self = this;
     notifier.performChange(RecursiveThingy.MULTIPLY_FIRST_N, function() {
       self[n-1] = self[n-1]*amount;
       self.multiplyFirstN(amount, n-1);
     });
 
     notifier.notify({
-      object: this,
       type: RecursiveThingy.MULTIPLY_FIRST_N,
       multiplied: amount,
       n: n
     });
   },
 }
 
 RecursiveThingy.observe = function(thingy, callback) {
   Object.observe(thingy, callback, [RecursiveThingy.MULTIPLY_FIRST_N]);
 }
@@ skipping 40 matching lines @@
       Array.prototype.push.apply(self, cut);
       self.reverse();
       self.sort(function() { return Math.random()* 2 - 1; });
       var cut = self.splice(0, 6);
       Array.prototype.push.apply(self, cut);
       self.reverse();
       self.sort(function() { return Math.random()* 2 - 1; });
     });
 
     notifier.notify({
-      object: this,
       type: DeckSuit.SHUFFLE
     });
   },
 }
 
 DeckSuit.observe = function(thingy, callback) {
   Object.observe(thingy, callback, [DeckSuit.SHUFFLE]);
 }
 
 DeckSuit.unobserve = function(thingy, callback) {
@@ skipping 1009 matching lines @@
     for (var n1 = 0; n1 < 3; ++n1)
       for (var n2 = 0; n2 < 3; ++n2)
         for (var i in mutation)
           TestFastElementsLength(mutation[i], b1 != 0, b2 != 0, 20*n1, 20*n2);
 
 for (var b1 = 0; b1 < 2; ++b1)
   for (var b2 = 0; b2 < 2; ++b2)
     for (var n = 0; n < 3; ++n)
       for (var i in mutationByIncr)
         TestFastElementsLength(mutationByIncr[i], b1 != 0, b2 != 0, 7*n, 7*n+1);