fix(scope): createChild now requires context

Author: mhevery

lib/core/scope.dart

@@ -249,8 +249,7 @@ class Scope {
   ScopeStream on(String name) =>
       _Streams.on(this, rootScope._exceptionHandler, name);
 
-  Scope createChild([Object childContext]) {
-    if (childContext == null) childContext = context;
+  Scope createChild(Object childContext) {
     var child = new Scope(childContext, rootScope, this,
                           _depth + 1, _nextChildIndex++,
                           watchGroup.newGroup(childContext),

lib/core_dom/common.dart

@@ -29,8 +29,10 @@ class DirectiveRef {
  * services from the provided modules.
  */
 Injector forceNewDirectivesAndFilters(Injector injector, List<Module> modules) {
-  modules.add(new Module()
-      ..factory(Scope, (i) => i.parent.get(Scope).createChild()));
+  modules.add(new Module()..factory(Scope, (i) {
+    var scope = i.parent.get(Scope);
+    return scope.createChild(new PrototypeMap(scope.context));
+  }));
   return injector.createChild(modules,
       forceNewInstances: [DirectiveMap, FilterMap]);
 }

test/core/scope_spec.dart

@@ -192,9 +192,9 @@ main() => describe('scope', () {
       }));
 
       it('children should point to root', inject((RootScope rootScope) {
-        var child = rootScope.createChild();
+        var child = rootScope.createChild(new PrototypeMap(rootScope.context));
         expect(child.rootScope).toEqual(rootScope);
-        expect(child.createChild().rootScope).toEqual(rootScope);
+        expect(child.createChild(new PrototypeMap(rootScope.context)).rootScope).toEqual(rootScope);
       }));
     });
 
@@ -206,10 +206,10 @@ main() => describe('scope', () {
 
 
       it('should point to parent', inject((RootScope rootScope) {
-        var child = rootScope.createChild();
+        var child = rootScope.createChild(new PrototypeMap(rootScope.context));
         expect(rootScope.parentScope).toEqual(null);
         expect(child.parentScope).toEqual(rootScope);
-        expect(child.createChild().parentScope).toEqual(child);
+        expect(child.createChild(new PrototypeMap(rootScope.context)).parentScope).toEqual(child);
       }));
     });
   });
@@ -226,7 +226,7 @@ main() => describe('scope', () {
 
       it(r'should add listener for both emit and broadcast events', inject((RootScope rootScope) {
         var log = '',
-        child = rootScope.createChild();
+        child = rootScope.createChild(new PrototypeMap(rootScope.context));
 
         eventFn(event) {
           expect(event).not.toEqual(null);
@@ -246,7 +246,7 @@ main() => describe('scope', () {
 
       it(r'should return a function that deregisters the listener', inject((RootScope rootScope) {
         var log = '';
-        var child = rootScope.createChild();
+        var child = rootScope.createChild(new PrototypeMap(rootScope.context));
         var subscription;
 
         eventFn(e) {