remove duplicate class members

Summary:
Flow currently allows duplicate members on classes. At runtime the "last" member wins out and all previous values for the member are discarded.
This diff manually removes duplicate members, and fixes resulting flow errors by converting methods to arrow function properties.

Reviewed By: pieterv

Differential Revision: D33664966

fbshipit-source-id: 0f712ac96af4df593c0918fcbadd70624ddde4a6

Author: bradzacher

Libraries/Animated/AnimatedEvent.js

@@ -145,7 +145,6 @@ function validateMapping(argMapping, args) {
 class AnimatedEvent {
   _argMapping: $ReadOnlyArray<?Mapping>;
   _listeners: Array<Function> = [];
-  _callListeners: Function;
   _attachedEvent: ?{detach: () => void, ...};
   __isNative: boolean;
 
@@ -160,7 +159,6 @@ class AnimatedEvent {
     if (config.listener) {
       this.__addListener(config.listener);
     }
-    this._callListeners = this._callListeners.bind(this);
     this._attachedEvent = null;
     this.__isNative = shouldUseNativeDriver(config);
   }
@@ -245,9 +243,9 @@ class AnimatedEvent {
     };
   }
 
-  _callListeners(...args: any) {
+  _callListeners = (...args: any) => {
     this._listeners.forEach(listener => listener(...args));
-  }
+  };
 }
 
 module.exports = {AnimatedEvent, attachNativeEvent};

Libraries/Network/XMLHttpRequest.js

@@ -136,7 +136,6 @@ class XMLHttpRequest extends (EventTarget(...XHR_EVENTS): any) {
   _lowerCaseResponseHeaders: Object;
   _method: ?string = null;
   _perfKey: ?string = null;
-  _response: string | ?Object;
   _responseType: ResponseType;
   _response: string = '';
   _sent: boolean;

packages/rn-tester/js/examples/AnimatedGratuitousApp/AnExApp.js

@@ -28,20 +28,16 @@ const NUM_CIRCLES = 30;
 class Circle extends React.Component<any, any> {
   longTimer: number;
 
-  _onLongPress: () => void;
-  _toggleIsActive: () => void;
   constructor(props: Object): void {
     super();
-    this._onLongPress = this._onLongPress.bind(this);
-    this._toggleIsActive = this._toggleIsActive.bind(this);
     this.state = {
       isActive: false,
       pan: new Animated.ValueXY(), // Vectors reduce boilerplate.  (step1: uncomment)
       pop: new Animated.Value(0), // Initial value.               (step2a: uncomment)
     };
   }
 
-  _onLongPress(): void {
+  _onLongPress = (): void => {
     const config = {tension: 40, friction: 3};
     this.state.pan.addListener(value => {
       // Async listener for state changes  (step1: uncomment)
@@ -90,7 +86,7 @@ class Circle extends React.Component<any, any> {
         this.props.onActivate();
       },
     );
-  }
+  };
 
   render(): React.Node {
     let handlers;
@@ -193,7 +189,7 @@ class Circle extends React.Component<any, any> {
       </Animated.View>
     );
   }
-  _toggleIsActive(velocity) {
+  _toggleIsActive = velocity => {
     const config = {tension: 30, friction: 7};
     if (this.state.isActive) {
       Animated.spring(this.props.openVal, {
@@ -215,11 +211,10 @@ class Circle extends React.Component<any, any> {
         }).start(); // (step4: uncomment)
       });
     }
-  }
+  };
 }
 
 class AnExApp extends React.Component<any, any> {
-  _onMove: (position: Point) => void;
   constructor(props: any): void {
     super(props);
     const keys = [];
@@ -231,7 +226,6 @@ class AnExApp extends React.Component<any, any> {
       restLayouts: [],
       openVal: new Animated.Value(0),
     };
-    this._onMove = this._onMove.bind(this);
   }
 
   render(): React.Node {
@@ -297,13 +291,13 @@ class AnExApp extends React.Component<any, any> {
     );
   }
 
-  _onMove(position: Point): void {
+  _onMove = (position: Point): void => {
     const newKeys = moveToClosest(this.state, position);
     if (newKeys !== this.state.keys) {
       LayoutAnimation.easeInEaseOut(); // animates layout update as one batch (step3: uncomment)
       this.setState({keys: newKeys});
     }
-  }
+  };
 }
 
 type Point = {

packages/rn-tester/js/examples/Image/ImageExample.js

@@ -339,16 +339,6 @@ class MultipleSourcesExample extends React.Component<
     });
   };
 
-  increaseImageSize = () => {
-    if (this.state.width >= 100) {
-      return;
-    }
-    this.setState({
-      width: this.state.width + 10,
-      height: this.state.height + 10,
-    });
-  };
-
   decreaseImageSize = () => {
     if (this.state.width <= 10) {
       return;
@@ -480,16 +470,6 @@ class OnLayoutExample extends React.Component<
     });
   };
 
-  increaseImageSize = () => {
-    if (this.state.width >= 100) {
-      return;
-    }
-    this.setState({
-      width: this.state.width + 10,
-      height: this.state.height + 10,
-    });
-  };
-
   decreaseImageSize = () => {
     if (this.state.width <= 10) {
       return;