Partial React Sync from 241c4467e...00d8e5b80

Summary:
- **[00d8e5b80](facebook/react@00d8e5b80 )**: [Fabric] Fix targetAsInstance dispatchEvent "cannot read property of null" (facebook#18156) //<Joshua Gross>//
- **[ad84625f8](facebook/react@ad84625f8 )**: [Native] Migrate focus/blur to call TextInputState with the host component (facebook#18068) //<Eli White>//
- **[edab5c074](facebook/react@edab5c074 )**: Re-throw errors thrown by the renderer at the root in the complete phase (facebook#18029) //<Andrew Clark>//
- **[a6dfe9aa4](facebook/react@a6dfe9aa4 )**: [Native] Delete NativeComponent and NativeMethodsMixin (facebook#18036) //<Eli White>//

Changelog:
[General][React] Partial React Sync from 241c4467e...00d8e5b80

Reviewed By: JoshuaGross

Differential Revision: D20153744

fbshipit-source-id: 09c5fec620370f1844a89af1c6ba2d487020216d

Libraries/Renderer/implementations/ReactFabric-dev.fb.js

@@ -3828,7 +3828,11 @@ function dispatchEvent(target, topLevelType, nativeEvent) {
 
   if (enableNativeTargetAsInstance) {
     if (targetFiber != null) {
-      eventTarget = targetFiber.stateNode.canonical;
+      var stateNode = targetFiber.stateNode; // Guard against Fiber being unmounted
+
+      if (stateNode != null) {
+        eventTarget = stateNode.canonical;
+      }
     }
   } else {
     eventTarget = nativeEvent.target;

Libraries/Renderer/implementations/ReactFabric-dev.js

@@ -3826,7 +3826,11 @@ function dispatchEvent(target, topLevelType, nativeEvent) {
 
   if (enableNativeTargetAsInstance) {
     if (targetFiber != null) {
-      eventTarget = targetFiber.stateNode.canonical;
+      var stateNode = targetFiber.stateNode; // Guard against Fiber being unmounted
+
+      if (stateNode != null) {
+        eventTarget = stateNode.canonical;
+      }
     }
   } else {
     eventTarget = nativeEvent.target;

Libraries/Renderer/implementations/ReactFabric-prod.fb.js

@@ -1467,9 +1467,12 @@ function batchedUpdates(fn, bookkeeping) {
 }
 function dispatchEvent(target, topLevelType, nativeEvent) {
   var eventTarget = null;
-  enableNativeTargetAsInstance
-    ? null != target && (eventTarget = target.stateNode.canonical)
-    : (eventTarget = nativeEvent.target);
+  if (enableNativeTargetAsInstance) {
+    if (null != target) {
+      var stateNode = target.stateNode;
+      null != stateNode && (eventTarget = stateNode.canonical);
+    }
+  } else eventTarget = nativeEvent.target;
   batchedUpdates(function() {
     var events = eventTarget;
     for (var events$jscomp$0 = null, i = 0; i < plugins.length; i++) {

Libraries/Renderer/implementations/ReactFabric-profiling.fb.js

@@ -1468,9 +1468,12 @@ function batchedUpdates(fn, bookkeeping) {
 }
 function dispatchEvent(target, topLevelType, nativeEvent) {
   var eventTarget = null;
-  enableNativeTargetAsInstance
-    ? null != target && (eventTarget = target.stateNode.canonical)
-    : (eventTarget = nativeEvent.target);
+  if (enableNativeTargetAsInstance) {
+    if (null != target) {
+      var stateNode = target.stateNode;
+      null != stateNode && (eventTarget = stateNode.canonical);
+    }
+  } else eventTarget = nativeEvent.target;
   batchedUpdates(function() {
     var events = eventTarget;
     for (var events$jscomp$0 = null, i = 0; i < plugins.length; i++) {