fix(ngAnimate): ensure animations are disabled upon bootstrap for structrual animations

Closes #5130

src/ngAnimate/animate.js

@@ -263,9 +263,16 @@ angular.module('ngAnimate', ['ng'])
 
       $rootElement.data(NG_ANIMATE_STATE, rootAnimateState);
 
-      // disable animations during bootstrap, but once we bootstrapped, enable animations
+      // disable animations during bootstrap, but once we bootstrapped, wait again
+      // for another digest until enabling animations. The reason why we digest twice
+      // is because all structural animations (enter, leave and move) all perform a
+      // post digest operation before animating. If we only wait for a single digest
+      // to pass then the structural animation would render its animation on page load.
+      // (which is what we're trying to avoid when the application first boots up.)
       $rootScope.$$postDigest(function() {
-        rootAnimateState.running = false;
+        $rootScope.$$postDigest(function() {
+          rootAnimateState.running = false;
+        });
       });
 
       function lookup(name) {

test/ng/directive/ngClassSpec.js

@@ -373,6 +373,10 @@ describe('ngClass animations', function() {
       // Enable animations by triggering the first item in the postDigest queue
       digestQueue.shift()();
 
+      // wait for the 2nd animation bootstrap digest to pass
+      $rootScope.$digest();
+      digestQueue.shift()();
+
       $rootScope.val = 'crazy';
       var element = angular.element('<div ng-class="val"></div>');
       jqLite($document[0].body).append($rootElement);