BI-60021 兼容性-fix内部nextTick在火狐下有兼容问题（先还原，已建任务研究）

dist/fix/fix.js

@@ -120,55 +120,38 @@ function _classCallCheck(instance, Constructor) { if (!(instance instanceof Cons
             }
         }
 
-        // Here we have async deferring wrappers using microtasks.
+        // An asynchronous deferring mechanism.
-        // In 2.5 we used (macro) tasks (in combination with microtasks).
+        // In pre 2.4, we used to use microtasks (Promise/MutationObserver)
-        // However, it has subtle problems when state is changed right before repaint
+        // but microtasks actually has too high a priority and fires in between
-        // (e.g. #6813, out-in transitions).
+        // supposedly sequential events (e.g. #4521, #6690) or even between
-        // Also, using (macro) tasks in event handler would cause some weird behaviors
+        // bubbling of the same event (#6566). Technically setImmediate should be
-        // that cannot be circumvented (e.g. #7109, #7153, #7546, #7834, #8109).
+        // the ideal choice, but it's not available everywhere; and the only polyfill
-        // So we now use microtasks everywhere, again.
+        // that consistently queues the callback after all DOM events triggered in the
-        // A major drawback of this tradeoff is that there are some scenarios
+        // same loop is by using MessageChannel.
-        // where microtasks have too high a priority and fire in between supposedly
+        /* istanbul ignore if */
-        // sequential events (e.g. #4521, #6690, which have workarounds)
+        if (typeof setImmediate !== 'undefined' && isNative(setImmediate)) {
-        // or even between bubbling of the same event (#6566).
-
-        // The nextTick behavior leverages the microtask queue, which can be accessed
-        // via either native Promise.then or MutationObserver.
-        // MutationObserver has wider support, however it is seriously bugged in
-        // UIWebView in iOS >= 9.3.3 when triggered in touch event handlers. It
-        // completely stops working after triggering a few times... so, if native
-        // Promise is available, we will use it:
-        /* istanbul ignore next, $flow-disable-line */
-        if (typeof Promise !== 'undefined' && isNative(Promise)) {
-            var p = Promise.resolve();
             timerFunc = function timerFunc() {
-                p.then(nextTickHandler);
+                setImmediate(nextTickHandler);
             };
-        } else if (!isIE && typeof MutationObserver !== 'undefined' && (isNative(MutationObserver) ||
+        } else if (typeof MessageChannel !== 'undefined' && (isNative(MessageChannel) ||
-        // PhantomJS and iOS 7.x
+        // PhantomJS
-        MutationObserver.toString() === '[object MutationObserverConstructor]')) {
+        MessageChannel.toString() === '[object MessageChannelConstructor]')) {
-            // Use MutationObserver where native Promise is not available,
+            var channel = new MessageChannel();
-            // e.g. PhantomJS, iOS7, Android 4.4
+            var port = channel.port2;
-            // (#6466 MutationObserver is unreliable in IE11)
+            channel.port1.onmessage = nextTickHandler;
-            var counter = 1;
-            var observer = new MutationObserver(nextTickHandler);
-            var textNode = document.createTextNode(String(counter));
-            observer.observe(textNode, {
-                characterData: true
-            });
             timerFunc = function timerFunc() {
-                counter = (counter + 1) % 2;
+                port.postMessage(1);
-                textNode.data = String(counter);
             };
-        } else if (typeof setImmediate !== 'undefined' && isNative(setImmediate)) {
+        } else
-            // Fallback to setImmediate.
+            /* istanbul ignore next */
-            // Technically it leverages the (macro) task queue,
+            if (typeof Promise !== 'undefined' && isNative(Promise)) {
-            // but it is still a better choice than setTimeout.
+                // use microtask in non-DOM environments, e.g. Weex
+                var p = Promise.resolve();
                 timerFunc = function timerFunc() {
-                setImmediate(nextTickHandler);
+                    p.then(nextTickHandler);
                 };
             } else {
-            // Fallback to setTimeout.
+                // fallback to setTimeout
                 timerFunc = function timerFunc() {
                     setTimeout(nextTickHandler, 0);
                 };