Use addEventListener instead of attachEvent in IE9

Author: nhunzaker

packages/react-dom/src/events/ChangeEventPlugin.js

@@ -135,7 +135,7 @@ if (ExecutionEnvironment.canUseDOM) {
 function startWatchingForValueChange(target, targetInst) {
   activeElement = target;
   activeElementInst = targetInst;
-  activeElement.attachEvent('onpropertychange', handlePropertyChange);
+  activeElement.addEventListener('onpropertychange', handlePropertyChange);
 }
 
 /**
@@ -146,7 +146,7 @@ function stopWatchingForValueChange() {
   if (!activeElement) {
     return;
   }
-  activeElement.detachEvent('onpropertychange', handlePropertyChange);
+  activeElement.removeEventListener('onpropertychange', handlePropertyChange);
   activeElement = null;
   activeElementInst = null;
 }

packages/react-dom/src/events/getEventTarget.js

@@ -17,7 +17,7 @@ import {TEXT_NODE} from '../shared/HTMLNodeType';
 function getEventTarget(nativeEvent) {
   // Fallback to nativeEvent.srcElement for IE9
   // https://github.com/facebook/react/issues/12506
-  let target = nativeEvent.target || nativeEvent.srcElement || window;
+  let target = nativeEvent.target || window;
 
   // Normalize SVG <use> element events #4963
   if (target.correspondingUseElement) {