js: Add _ref property in view,store ref, for combine action in mobx

doric-js/lib/src/ui/view.d.ts

@@ -135,6 +135,7 @@ export declare abstract class View implements Modeling {
     flexConfig?: FlexConfig;
     set props(props: Partial<this>);
     set parent(v: Group);
+    private _ref?;
     set ref(ref: Ref<this>);
     doAnimation(context: BridgeContext, animation: IAnimation): Promise<void>;
     clearAnimation(context: BridgeContext, animation: IAnimation): Promise<void>;

doric-js/lib/src/ui/view.js

@@ -227,6 +227,7 @@ export class View {
     }
     set ref(ref) {
         ref.current = this;
+        this._ref = ref;
     }
     doAnimation(context, animation) {
         return this.nativeChannel(context, "doAnimation")(animation.toModel()).then((args) => {