fix(scope): honor $skipAutoDigest on non-root scopes

Close #391

lib/core/scope.dart

@@ -102,8 +102,8 @@ class Scope implements Map {
   }
 
   _autoDigestOnTurnDone() {
-    if (_skipAutoDigest) {
-      _skipAutoDigest = false;
+    if ($root._skipAutoDigest) {
+      $root._skipAutoDigest = false;
     } else {
       $digest();
     }
@@ -393,7 +393,7 @@ class Scope implements Map {
    * auto-digesting scope.
    */
   $$verifyDigestWillRun() {
-    assert(!_skipAutoDigest);
+    assert(!$root._skipAutoDigest);
     _zone.assertInTurn();
   }
 
@@ -632,12 +632,12 @@ class Scope implements Map {
    * you just scheduled or are otherwise certain of an impending VM turn and the
    * digest at the end of that turn is sufficient.  You should be able to answer
    * "No" to the question "Is there any other code that is aware that this VM
-   * turn occured and therefore expected a digest?".  If your answer is "Yes",
+   * turn occurred and therefore expected a digest?".  If your answer is "Yes",
    * then you run the risk that the very next VM turn is not for your event and
    * now that other code runs in that turn and sees stale values.
    *
    * You might call this function, for instance, from an event listener where,
-   * though the event occured, you need to wait for another event before you can
+   * though the eventoccurredd, you need to wait for another event before you can
    * perform something meaningful.  You might schedule that other event,
    * set a flag for the handler of the other event to recognize, etc. and then
    * call this method to skip the digest this cycle.  Note that you should call
@@ -647,7 +647,7 @@ class Scope implements Map {
    */
   $skipAutoDigest() {
     _zone.assertInTurn();
-    _skipAutoDigest = true;
+    $root._skipAutoDigest = true;
   }
 
 

test/core/scope_spec.dart

@@ -19,6 +19,7 @@ main() {
 
     describe(r'$root', () {
       it(r'should point to itself', inject((Scope $rootScope) {
+        expect($rootScope.$root).toEqual($rootScope);
         expect($rootScope.$root).toEqual($rootScope);
         expect($rootScope.$root).toBeTruthy();
       }));
@@ -106,6 +107,22 @@ main() {
         expect(digestedValue).toEqual(1);
       }));
 
+      it(r'should skip auto digest if requested on any scope', inject((Scope $rootScope) {
+        var scope = $rootScope.$new();
+        var digestedValue = 0;
+        scope.a = 1;
+        scope.$watch('a', (newValue, oldValue, _this) {
+          digestedValue = newValue;
+        });
+        expect(digestedValue).toEqual(0);
+        zone.run(() {
+          scope.$skipAutoDigest();
+        });
+        expect(digestedValue).toEqual(0);
+        zone.run(noop);
+        expect(digestedValue).toEqual(1);
+      }));
+
       it(r'should throw exception if asked to skip auto digest outside of a turn',
          inject((Scope $rootScope) {
         var digestedValue = 0;