badgeColor property

Summary:
**motivation:**

make possible to use new tab bar item property

![1476033023249](https://cloud.githubusercontent.com/assets/1488195/19222245/f4c1292c-8e64-11e6-8a29-7b95b45e153c.jpg)
Closes https://github.com/facebook/react-native/pull/10315

Differential Revision: D4000011

Pulled By: mmmulani

fbshipit-source-id: 5c00b0b5f56c551cc4151fcc030da6c8bc1a3649

Examples/UIExplorer/js/TabBarIOSExample.js

@@ -73,6 +73,7 @@ class TabBarExample extends React.Component {
         <TabBarIOS.Item
           systemIcon="history"
           badge={this.state.notifCount > 0 ? this.state.notifCount : undefined}
+          badgeColor="black"
           selected={this.state.selectedTab === 'redTab'}
           onPress={() => {
             this.setState({

Libraries/Components/TabBarIOS/TabBarItemIOS.ios.js

@@ -16,6 +16,7 @@ var React = require('React');
 var StaticContainer = require('StaticContainer.react');
 var StyleSheet = require('StyleSheet');
 var View = require('View');
+var ColorPropType = require('ColorPropType');
 
 var requireNativeComponent = require('requireNativeComponent');
 
@@ -29,6 +30,10 @@ class TabBarItemIOS extends React.Component {
       React.PropTypes.string,
       React.PropTypes.number,
     ]),
+    /**
+     * Background color for the badge. Available since iOS 10.
+     */
+    badgeColor: ColorPropType,
     /**
      * Items comes with a few predefined system icons. Note that if you are
      * using them, the title and selectedIcon will be overridden with the

React/Views/RCTTabBarItem.m

@@ -105,6 +105,13 @@ RCT_ENUM_CONVERTER(UITabBarSystemItem, (@{
   }
 }
 
+- (void)setBadgeColor:(UIColor *)bagdeColor
+{
+#if defined(__IPHONE_OS_VERSION_MAX_ALLOWED) && __IPHONE_OS_VERSION_MAX_ALLOWED >= __IPHONE_10_0
+  _barItem.badgeColor = bagdeColor;
+#endif
+}
+
 - (UIViewController *)reactViewController
 {
   return self.superview.reactViewController;

React/Views/RCTTabBarItemManager.m

@@ -28,6 +28,7 @@ RCT_EXPORT_VIEW_PROPERTY(icon, UIImage)
 RCT_EXPORT_VIEW_PROPERTY(selectedIcon, UIImage)
 RCT_EXPORT_VIEW_PROPERTY(systemIcon, UITabBarSystemItem)
 RCT_EXPORT_VIEW_PROPERTY(onPress, RCTBubblingEventBlock)
+RCT_EXPORT_VIEW_PROPERTY(badgeColor, UIColor)
 RCT_CUSTOM_VIEW_PROPERTY(title, NSString, RCTTabBarItem)
 {
   view.barItem.title = json ? [RCTConvert NSString:json] : defaultView.barItem.title;