Made metagetter only call underlying get functions once, switched to included bind function

Author: jdavidberger

src/observer/index.js

@@ -182,8 +182,8 @@ function defineReactive (obj, key, val) {
     var property = Object.getOwnPropertyDescriptor(obj, key)
     if (property && property.get && property.set) {
       Object.defineProperty(target, 'val', {
-        get: property.get.bind(obj),
-        set: property.set.bind(obj)
+        get: _.bind(property.get, obj),
+        set: _.bind(property.set, obj)
       })
     }
   }
@@ -193,14 +193,15 @@ function defineReactive (obj, key, val) {
     enumerable: true,
     configurable: true,
     get: function metaGetter () {
+      var val = target.val
       if (Dep.target) {
         dep.depend()
         if (childOb) {
           childOb.dep.depend()
         }
-        if (_.isArray(target.val)) {
-          for (var e, i = 0, l = target.val.length; i < l; i++) {
-            e = target.val[i]
+        if (_.isArray(val)) {
+          for (var e, i = 0, l = val.length; i < l; i++) {
+            e = val[i]
             e && e.__ob__ && e.__ob__.dep.depend()
           }
         }

test/unit/lib/util.js

@@ -2,15 +2,6 @@ var scope = typeof window === 'undefined'
   ? global
   : window
 
-// Some versions of phantomjs doesn't have bind defined. 
-// See https://github.com/ariya/phantomjs/issues/10522
-Function.prototype.bind = Function.prototype.bind || function (thisp) {
-  var fn = this;
-  return function () {
-    return fn.apply(thisp, arguments);
-  };
-};
-
 scope.hasWarned = function (_, msg, silent) {
   var count = _.warn.calls.count()
   while (count--) {