Drop handling for ms and O prefixes for CSS transition and animation events. (#13133)

Internet Explorer never needed the prefix and Opera 11.5 is no longer supported by React.

Author: realityking

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

@@ -20,8 +20,6 @@ function makePrefixMap(styleProp, eventName) {
   prefixes[styleProp.toLowerCase()] = eventName.toLowerCase();
   prefixes['Webkit' + styleProp] = 'webkit' + eventName;
   prefixes['Moz' + styleProp] = 'moz' + eventName;
-  prefixes['ms' + styleProp] = 'MS' + eventName;
-  prefixes['O' + styleProp] = 'o' + eventName.toLowerCase();
 
   return prefixes;
 }