Removing 'isEventSupported'

src/eventPlugins/SelectEventPlugin.js

@@ -26,7 +26,6 @@ var ReactInputSelection = require('ReactInputSelection');
 var SyntheticEvent = require('SyntheticEvent');
 
 var getActiveElement = require('getActiveElement');
-var isEventSupported = require('isEventSupported');
 var isTextInputElement = require('isTextInputElement');
 var keyOf = require('keyOf');
 var shallowEqual = require('shallowEqual');