fix(parse): support parsing objects created with null prototype

Author: HeberLZ

src/ng/parse.js

@@ -946,10 +946,10 @@ function getterFn(path, options, fullExp) {
   return fn;
 }
 
-var objectValueOf = Object.prototype.valueOf.call;
+var objectValueOf = Object.prototype.valueOf;
 
 function getValueOf(value) {
-  return isFunction(value.valueOf) ? value.valueOf() : objectValueOf(value);
+  return isFunction(value.valueOf) ? value.valueOf() : objectValueOf.call(value);
 }
 
 ///////////////////////////////////

test/ng/parseSpec.js

@@ -1460,7 +1460,7 @@ describe('parser', function() {
           expect(watcherCalls).toBe(1);
         }));
 
-        it("should always reevaluate filters with non-primitive input created with Object.create(null)",
+        it("should always reevaluate filters with non-primitive input created with null prototype",
             inject(function($parse) {
           var filterCalls = 0;
           $filterProvider.register('foo', valueFn(function(input) {