feat(directive-injector): component directive injector injects parent

BREAKING_CHANGE:
When asked for DirectiveInjector, ComponentDirectiveInjector injects
parent. When asked for ComponentDirectiveInjector it injects self.

Before:
MyComponent(DirectiveInjector di) { }

After:
MyComponent(ComponentDirectiveInjector cdi, DirectiveInjector di) { }

where before di = after cdi, before di.parent = after di.

Closes #1351

lib/core_dom/directive_injector.dart

@@ -20,6 +20,7 @@ var _TAG_GET = new UserTag('DirectiveInjector.get()');
 var _TAG_INSTANTIATE = new UserTag('DirectiveInjector.instantiate()');
 
 final DIRECTIVE_INJECTOR_KEY = new Key(DirectiveInjector);
+final COMPONENT_DIRECTIVE_INJECTOR_KEY = new Key(ComponentDirectiveInjector);
 final CONTENT_PORT_KEY = new Key(ContentPort);
 final TEMPLATE_LOADER_KEY = new Key(TemplateLoader);
 final SHADOW_ROOT_KEY = new Key(ShadowRoot);
@@ -48,7 +49,8 @@ const int TEMPLATE_LOADER_KEY_ID    = 14;
 const int SHADOW_ROOT_KEY_ID        = 15;
 const int CONTENT_PORT_KEY_ID       = 16;
 const int EVENT_HANDLER_KEY_ID      = 17;
-const int KEEP_ME_LAST              = 18;
+const int COMPONENT_DIRECTIVE_INJECTOR_KEY_ID = 18;
+const int KEEP_ME_LAST              = 19;
 
 EventHandler eventHandler(DirectiveInjector di) => di._eventHandler;
 
@@ -74,6 +76,7 @@ class DirectiveInjector implements DirectiveBinder {
     CONTENT_PORT_KEY.uid       = CONTENT_PORT_KEY_ID;
     EVENT_HANDLER_KEY.uid      = EVENT_HANDLER_KEY_ID;
     ANIMATE_KEY.uid            = ANIMATE_KEY_ID;
+    COMPONENT_DIRECTIVE_INJECTOR_KEY.uid = COMPONENT_DIRECTIVE_INJECTOR_KEY_ID;
     for(var i = 1; i < KEEP_ME_LAST; i++) {
       if (_KEYS[i].uid != i) throw 'MISSORDERED KEYS ARRAY: ${_KEYS} at $i';
     }
@@ -97,6 +100,7 @@ class DirectiveInjector implements DirectiveBinder {
       , SHADOW_ROOT_KEY
       , CONTENT_PORT_KEY
       , EVENT_HANDLER_KEY
+      , COMPONENT_DIRECTIVE_INJECTOR_KEY
       , KEEP_ME_LAST
       ];
 
@@ -398,12 +402,18 @@ class ComponentDirectiveInjector extends DirectiveInjector {
                         EventHandler eventHandler, Scope scope,
                         this._templateLoader, this._shadowRoot, this._contentPort)
       : super(parent, appInjector, parent._node, parent._nodeAttrs, eventHandler, scope,
-              parent._animate);
+              parent._animate) {
+    // A single component creates a ComponentDirectiveInjector and its DirectiveInjector parent,
+    // so parent should never be null.
+    assert(parent != null);
+  }
 
   Object _getById(int keyId) {
     switch(keyId) {
       case TEMPLATE_LOADER_KEY_ID: return _templateLoader;
       case SHADOW_ROOT_KEY_ID: return _shadowRoot;
+      case DIRECTIVE_INJECTOR_KEY_ID: return _parent;
+      case COMPONENT_DIRECTIVE_INJECTOR_KEY_ID: return this;
       default: return super._getById(keyId);
     }
   }

test/core_dom/compiler_spec.dart

@@ -82,7 +82,8 @@ void main() {
           ..bind(ScopeAwareComponent)
           ..bind(Parent, toValue: null)
           ..bind(Child)
-          ..bind(ChildTemplateComponent);
+          ..bind(ChildTemplateComponent)
+          ..bind(InjectorDependentComponent);
     });
 
     beforeEach((TestBed tb) => _ = tb);
@@ -676,6 +677,13 @@ void main() {
         expect(logger.length).toEqual(2);
       }));
 
+      it('should inject the correct Injectors - Directive and ComponentDirective', async(() {
+        _.compile('<cmp-inj></cmp-inj>');
+        _.rootScope.apply();
+        microLeap();
+        // assertions are in the component constructor.
+      }));
+
       describe('lifecycle', () {
         beforeEachModule((Module module) {
           var httpBackend = new MockHttpBackend();
@@ -1553,3 +1561,15 @@ class OnceInside {
   set v(x) { log(x); ot = "($x)"; }
   OnceInside(Logger this.log) { log('!'); }
 }
+
+@Component(
+    selector: 'cmp-inj')
+class InjectorDependentComponent {
+  DirectiveInjector i;
+  ComponentDirectiveInjector cdi;
+  InjectorDependentComponent(this.i, this.cdi) {
+    expect(i).toBeAnInstanceOf(DirectiveInjector);
+    expect(cdi).toBeAnInstanceOf(ComponentDirectiveInjector);
+    expect(cdi.parent).toBe(i);
+  }
+}