Fix <TextInput autoFocus /> property

update platform detections

Author: ptmt

Examples/UIExplorer/DragnDropExample.osx.js

@@ -49,8 +49,8 @@ var DragExample = React.createClass({
         onDragEnter={() => this.setState({dragOver: true})}
         onDragLeave={() => this.setState({dragOver: false})}
         onDrop={(e) => this.setState({files: e.nativeEvent.files, dragOver: false})}>
-        <Text style={{fontSize: 14, color: 'white'}}>
-          {this.state.files ? this.state.files : 'Drag here a file'}
+        <Text style={{fontSize: 14, color: 'black'}}>
+          {this.state.files.length > 0 ? this.state.files : 'Drag here a file'}
         </Text>
 
       </View>

Libraries/Components/TextInput/TextInputState.js

@@ -40,7 +40,7 @@ var TextInputState = {
   focusTextInput: function(textFieldID: ?number) {
     if (this._currentlyFocusedID !== textFieldID && textFieldID !== null) {
       this._currentlyFocusedID = textFieldID;
-      if (Platform.OS === 'ios') {
+      if (Platform.OS === 'ios' || Platform.OS === 'osx') {
         UIManager.focus(textFieldID);
       } else if (Platform.OS === 'android') {
         UIManager.dispatchViewManagerCommand(