perf($rootScope): change 'this' scope variable to a $parse keyword

Author: jbedard

src/ng/parse.js

@@ -92,6 +92,11 @@ forEach({
   CONSTANTS[name] = constantGetter;
 });
 
+//Not quite a constant, but can be lex/parsed the same
+CONSTANTS['this'] = function(self) { return self; };
+CONSTANTS['this'].sharedGetter = true;
+
+
 //Operators - will be wrapped by binaryFn/unaryFn/assignment/filter
 var OPERATORS = extend(createMap(), {
     /* jshint bitwise : false */

src/ng/rootScope.js

@@ -128,7 +128,7 @@ function $RootScopeProvider(){
       this.$$phase = this.$parent = this.$$watchers =
                      this.$$nextSibling = this.$$prevSibling =
                      this.$$childHead = this.$$childTail = null;
-      this['this'] = this.$root =  this;
+      this.$root =  this;
       this.$$destroyed = false;
       this.$$asyncQueue = [];
       this.$$postDigestQueue = [];
@@ -212,7 +212,6 @@ function $RootScopeProvider(){
           }
           child = new this.$$ChildScope();
         }
-        child['this'] = child;
         child.$parent = this;
         child.$$prevSibling = this.$$childTail;
         if (this.$$childHead) {

test/ng/rootScopeSpec.js

@@ -52,7 +52,7 @@ describe('Scope', function() {
 
   describe('this', function() {
     it('should have a \'this\'', inject(function($rootScope) {
-      expect($rootScope['this']).toEqual($rootScope);
+      expect($rootScope.$eval('this')).toEqual($rootScope);
     }));
   });