Support tintColor and thumbTintColor for Switch on Android

Summary:
**Motivation**

`Switch` on Android doesn't allow changing the colors unlike iOS. Changing the colors is desirable in a lot of cases to match the brand colors.

The PR adds support for the `tintColor`, `onTintColor` and `thumbTintColor` props on Android, which more or less behave the same as iOS. The only difference is `tintColor` styles the border color on iOS, whereas it styles the background color on Android.

**Test plan (required)**

Run UIExplorer with the changes, and ensure that the switch example works properly. Here are screenshots from iOS and Android to compare.

![image](https://cloud.githubusercontent.com/assets/1174278/22018002/b05d6482-dcd2-11e6-9c00-f55a71d6ce29.png)

![image](https://cloud.githubusercontent.com/assets/1174278/22018012/b923e974-dcd2-11e6-8d4e-86994f5a66e6.png)

cc brentvatne
Closes https://github.com/facebook/react-native/pull/11940

Differential Revision: D4427491

fbshipit-source-id: 16c569d2e2261daaea93fffa83198f8f6b59a6c8

Examples/UIExplorer/js/SwitchExample.js

@@ -147,15 +147,12 @@ var examples = [
   {
     title: 'Switches are controlled components',
     render(): React.Element<any> { return <Switch />; }
-  }
+  },
-];
+  {
-
-if (Platform.OS === 'ios') {
-  examples.push({
     title: 'Custom colors can be provided',
     render(): React.Element<any> { return <ColorSwitchExample />; }
-  });
   }
+];
 
 exports.title = '<Switch>';
 exports.displayName = 'SwitchExample';

Libraries/Components/Switch/Switch.js

@@ -20,6 +20,8 @@ var View = require('View');
 
 var requireNativeComponent = require('requireNativeComponent');
 
+var { PropTypes } = React;
+
 type DefaultProps = {
   value: boolean,
   disabled: boolean,
@@ -43,34 +45,31 @@ var Switch = React.createClass({
      * The value of the switch.  If true the switch will be turned on.
      * Default value is false.
      */
-    value: React.PropTypes.bool,
+    value: PropTypes.bool,
     /**
      * If true the user won't be able to toggle the switch.
      * Default value is false.
      */
-    disabled: React.PropTypes.bool,
+    disabled: PropTypes.bool,
     /**
      * Invoked with the new value when the value changes.
      */
-    onValueChange: React.PropTypes.func,
+    onValueChange: PropTypes.func,
     /**
      * Used to locate this view in end-to-end tests.
      */
-    testID: React.PropTypes.string,
+    testID: PropTypes.string,
 
     /**
-     * Border color when the switch is turned off.
+     * Border color on iOS and background color on Android when the switch is turned off.
-     * @platform ios
      */
     tintColor: ColorPropType,
     /**
      * Background color when the switch is turned on.
-     * @platform ios
      */
     onTintColor: ColorPropType,
     /**
      * Color of the foreground switch grip.
-     * @platform ios
      */
     thumbTintColor: ColorPropType,
   },
@@ -104,6 +103,7 @@ var Switch = React.createClass({
       props.enabled = !this.props.disabled;
       props.on = this.props.value;
       props.style = this.props.style;
+      props.trackTintColor = this.props.value ? this.props.onTintColor : this.props.tintColor;
     } else if (Platform.OS === 'ios') {
       props.style = [styles.rctSwitchIOS, this.props.style];
     }
@@ -126,11 +126,18 @@ var styles = StyleSheet.create({
 
 if (Platform.OS === 'android') {
   var RCTSwitch = requireNativeComponent('AndroidSwitch', Switch, {
-    nativeOnly: { onChange: true, on: true, enabled: true }
+    nativeOnly: {
+      onChange: true,
+      on: true,
+      enabled: true,
+      trackTintColor: true,
+    }
   });
 } else {
   var RCTSwitch = requireNativeComponent('RCTSwitch', Switch, {
-    nativeOnly: { onChange: true }
+    nativeOnly: {
+      onChange: true
+    }
   });
 }
 

ReactAndroid/src/main/java/com/facebook/react/views/switchview/ReactSwitchManager.java

@@ -10,6 +10,7 @@
 // switchview because switch is a keyword
 package com.facebook.react.views.switchview;
 
+import android.graphics.PorterDuff;
 import android.view.View;
 import android.view.ViewGroup;
 import android.widget.CompoundButton;
@@ -117,6 +118,24 @@ public class ReactSwitchManager extends SimpleViewManager<ReactSwitch> {
     view.setOnCheckedChangeListener(ON_CHECKED_CHANGE_LISTENER);
   }
 
+  @ReactProp(name = "thumbTintColor", customType = "Color")
+  public void setThumbTintColor(ReactSwitch view, Integer color) {
+    if (color == null) {
+      view.getThumbDrawable().clearColorFilter();
+    } else {
+      view.getThumbDrawable().setColorFilter(color, PorterDuff.Mode.MULTIPLY);
+    }
+  }
+
+  @ReactProp(name = "trackTintColor", customType = "Color")
+  public void setTrackTintColor(ReactSwitch view, Integer color) {
+    if (color == null) {
+      view.getTrackDrawable().clearColorFilter();
+    } else {
+      view.getTrackDrawable().setColorFilter(color, PorterDuff.Mode.MULTIPLY);
+    }
+  }
+
   @Override
   protected void addEventEmitters(final ThemedReactContext reactContext, final ReactSwitch view) {
     view.setOnCheckedChangeListener(ON_CHECKED_CHANGE_LISTENER);