Add emitting view to onChildStartedNativeGesture callback

Summary:
Changelog:
[Android][Changed] RootView's onChildStartedNativeGesture now takes the child view as its first argument

Reviewed By: philIip

Differential Revision: D31399515

fbshipit-source-id: b9438f6118e604a04799ef67d0b46303a06d6434

ReactAndroid/src/main/java/com/facebook/react/ReactRootView.java

@@ -184,7 +184,7 @@ protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
   }
 
   @Override
-  public void onChildStartedNativeGesture(MotionEvent androidEvent) {
+  public void onChildStartedNativeGesture(MotionEvent ev) {
     if (mReactInstanceManager == null
         || !mIsAttachedToInstance
         || mReactInstanceManager.getCurrentReactContext() == null) {
@@ -200,10 +200,15 @@ public void onChildStartedNativeGesture(MotionEvent androidEvent) {
 
     if (uiManager != null) {
       EventDispatcher eventDispatcher = uiManager.getEventDispatcher();
-      mJSTouchDispatcher.onChildStartedNativeGesture(androidEvent, eventDispatcher);
+      mJSTouchDispatcher.onChildStartedNativeGesture(ev, eventDispatcher);
     }
   }
 
+  @Override
+  public void onChildStartedNativeGesture(View childView, MotionEvent ev) {
+    onChildStartedNativeGesture(ev);
+  }
+
   @Override
   public boolean onInterceptTouchEvent(MotionEvent ev) {
     dispatchJSTouchEvent(ev);

ReactAndroid/src/main/java/com/facebook/react/uimanager/RootView.java

@@ -8,6 +8,7 @@
 package com.facebook.react.uimanager;
 
 import android.view.MotionEvent;
+import android.view.View;
 
 /** Interface for the root native view of a React native application. */
 public interface RootView {
@@ -16,7 +17,10 @@ public interface RootView {
    * Called when a child starts a native gesture (e.g. a scroll in a ScrollView). Should be called
    * from the child's onTouchIntercepted implementation.
    */
-  void onChildStartedNativeGesture(MotionEvent androidEvent);
+  void onChildStartedNativeGesture(View childView, MotionEvent ev);
+
+  /** @deprecated */
+  void onChildStartedNativeGesture(MotionEvent ev);
 
   void handleException(Throwable t);
 }

ReactAndroid/src/main/java/com/facebook/react/uimanager/events/NativeGestureUtil.java

@@ -23,6 +23,6 @@ public class NativeGestureUtil {
    * @param event the MotionEvent that caused the gesture to be started
    */
   public static void notifyNativeGestureStarted(View view, MotionEvent event) {
-    RootViewUtil.getRootView(view).onChildStartedNativeGesture(event);
+    RootViewUtil.getRootView(view).onChildStartedNativeGesture(view, event);
   }
 }

ReactAndroid/src/main/java/com/facebook/react/views/modal/ReactModalHostView.java

@@ -528,8 +528,13 @@ public boolean onTouchEvent(MotionEvent event) {
     }
 
     @Override
-    public void onChildStartedNativeGesture(MotionEvent androidEvent) {
-      mJSTouchDispatcher.onChildStartedNativeGesture(androidEvent, mEventDispatcher);
+    public void onChildStartedNativeGesture(MotionEvent ev) {
+      mJSTouchDispatcher.onChildStartedNativeGesture(ev, mEventDispatcher);
+    }
+
+    @Override
+    public void onChildStartedNativeGesture(View childView, MotionEvent ev) {
+      mJSTouchDispatcher.onChildStartedNativeGesture(ev, mEventDispatcher);
     }
 
     @Override