Merge scroll changed workflow into scroll helper class

Summary:
This diff address [comment](https://www.internalfb.com/diff/D32372180 (073195991bfdf4c96490c65f9c0cf00d09356188)?dst_version_fbid=444635297227339&transaction_fbid=636262217544650) to merge workflow that notify Fabric state changes when scroll changed.

Changelog:
[Internal]

Reviewed By: javache

Differential Revision: D32500423

fbshipit-source-id: 8701f7ac885bf755e026b70554cb4a2ebb1af527

ReactAndroid/src/main/java/com/facebook/react/views/scroll/ReactHorizontalScrollView.java

@@ -432,13 +432,7 @@ protected void onScrollChanged(int x, int y, int oldX, int oldY) {
         updateClippingRect();
       }
 
-      // Race an UpdateState with every onScroll. This makes it more likely that, in Fabric,
-      // when JS processes the scroll event, the C++ ShadowNode representation will have a
-      // "more correct" scroll position. It will frequently be /incorrect/ but this decreases
-      // the error as much as possible.
-      ReactScrollViewHelper.updateStateOnScroll(this);
-
-      ReactScrollViewHelper.emitScrollEvent(
+      ReactScrollViewHelper.updateStateOnScrollChanged(
           this,
           mOnScrollDispatchHelper.getXFlingVelocity(),
           mOnScrollDispatchHelper.getYFlingVelocity());
@@ -521,7 +515,7 @@ public boolean onTouchEvent(MotionEvent ev) {
     mVelocityHelper.calculateVelocity(ev);
     int action = ev.getAction() & MotionEvent.ACTION_MASK;
     if (action == MotionEvent.ACTION_UP && mDragging) {
-      ReactScrollViewHelper.updateStateOnScroll(this);
+      ReactScrollViewHelper.updateFabricScrollState(this);
 
       float velocityX = mVelocityHelper.getXVelocity();
       float velocityY = mVelocityHelper.getYVelocity();
@@ -769,7 +763,7 @@ public void run() {
               mRunning = true;
             } else {
               // There has not been a scroll update since the last time this Runnable executed.
-              ReactScrollViewHelper.updateStateOnScroll(ReactHorizontalScrollView.this);
+              ReactScrollViewHelper.updateFabricScrollState(ReactHorizontalScrollView.this);
 
               // We keep checking for updates until the ScrollView has "stabilized" and hasn't
               // scrolled for N consecutive frames. This number is arbitrary: big enough to catch
@@ -1178,7 +1172,7 @@ public void scrollTo(int x, int y) {
     // to the last item in the list, but that item cannot be move to the start position of the view.
     final int actualX = getScrollX();
     final int actualY = getScrollY();
-    ReactScrollViewHelper.updateStateOnScroll(this, actualX, actualY);
+    ReactScrollViewHelper.updateFabricScrollState(this, actualX, actualY);
     setPendingContentOffsets(actualX, actualY);
   }
 

ReactAndroid/src/main/java/com/facebook/react/views/scroll/ReactScrollView.java

@@ -312,13 +312,7 @@ protected void onScrollChanged(int x, int y, int oldX, int oldY) {
         updateClippingRect();
       }
 
-      // Race an UpdateState with every onScroll. This makes it more likely that, in Fabric,
-      // when JS processes the scroll event, the C++ ShadowNode representation will have a
-      // "more correct" scroll position. It will frequently be /incorrect/ but this decreases
-      // the error as much as possible.
-      ReactScrollViewHelper.updateStateOnScroll(this);
-
-      ReactScrollViewHelper.emitScrollEvent(
+      ReactScrollViewHelper.updateStateOnScrollChanged(
           this,
           mOnScrollDispatchHelper.getXFlingVelocity(),
           mOnScrollDispatchHelper.getYFlingVelocity());
@@ -359,7 +353,7 @@ public boolean onTouchEvent(MotionEvent ev) {
     mVelocityHelper.calculateVelocity(ev);
     int action = ev.getAction() & MotionEvent.ACTION_MASK;
     if (action == MotionEvent.ACTION_UP && mDragging) {
-      ReactScrollViewHelper.updateStateOnScroll(this);
+      ReactScrollViewHelper.updateFabricScrollState(this);
 
       float velocityX = mVelocityHelper.getXVelocity();
       float velocityY = mVelocityHelper.getYVelocity();
@@ -558,7 +552,7 @@ public void run() {
               mRunning = true;
             } else {
               // There has not been a scroll update since the last time this Runnable executed.
-              ReactScrollViewHelper.updateStateOnScroll(ReactScrollView.this);
+              ReactScrollViewHelper.updateFabricScrollState(ReactScrollView.this);
 
               // We keep checking for updates until the ScrollView has "stabilized" and hasn't
               // scrolled for N consecutive frames. This number is arbitrary: big enough to catch
@@ -953,7 +947,7 @@ public void scrollTo(int x, int y) {
     // to the last item in the list, but that item cannot be move to the start position of the view.
     final int actualX = getScrollX();
     final int actualY = getScrollY();
-    ReactScrollViewHelper.updateStateOnScroll(this, actualX, actualY);
+    ReactScrollViewHelper.updateFabricScrollState(this, actualX, actualY);
     setPendingContentOffsets(actualX, actualY);
   }
 

ReactAndroid/src/main/java/com/facebook/react/views/scroll/ReactScrollViewHelper.java

@@ -342,7 +342,7 @@ void smoothScrollTo(final T scrollView, final int x, final int y) {
       scrollView.startFlingAnimator(scrollY, y);
     }
 
-    updateStateOnScroll(scrollView, x, y);
+    updateFabricScrollState(scrollView, x, y);
   }
 
   /** Get current (x, y) position or position after current animation finishes, if any. */
@@ -386,8 +386,8 @@ Point getPostAnimationScroll(final T scrollView, final boolean isPositiveVelocit
           T extends
               ViewGroup & FabricViewStateManager.HasFabricViewStateManager & HasScrollState
                   & HasFlingAnimator>
-      boolean updateStateOnScroll(final T scrollView) {
-    return updateStateOnScroll(scrollView, scrollView.getScrollX(), scrollView.getScrollY());
+      boolean updateFabricScrollState(final T scrollView) {
+    return updateFabricScrollState(scrollView, scrollView.getScrollX(), scrollView.getScrollY());
   }
 
   /**
@@ -397,11 +397,11 @@ boolean updateStateOnScroll(final T scrollView) {
           T extends
               ViewGroup & FabricViewStateManager.HasFabricViewStateManager & HasScrollState
                   & HasFlingAnimator>
-      boolean updateStateOnScroll(final T scrollView, final int scrollX, final int scrollY) {
+      boolean updateFabricScrollState(final T scrollView, final int scrollX, final int scrollY) {
     if (DEBUG_MODE) {
       FLog.i(
           TAG,
-          "updateStateOnScroll[%d] scrollX %d scrollY %d",
+          "updateFabricScrollState[%d] scrollX %d scrollY %d",
           scrollView.getId(),
           scrollX,
           scrollY);
@@ -448,7 +448,7 @@ void forceUpdateState(final T scrollView) {
     if (DEBUG_MODE) {
       FLog.i(
           TAG,
-          "updateStateOnScroll[%d] scrollX %d scrollY %d fabricScrollX",
+          "updateFabricScrollState[%d] scrollX %d scrollY %d fabricScrollX",
           scrollView.getId(),
           scrollX,
           scrollY,
@@ -471,6 +471,20 @@ public WritableMap getStateUpdate() {
             });
   }
 
+  public static <
+          T extends
+              ViewGroup & FabricViewStateManager.HasFabricViewStateManager & HasScrollState
+                  & HasFlingAnimator>
+      void updateStateOnScrollChanged(
+          final T scrollView, final float xVelocity, final float yVelocity) {
+    // Race an UpdateState with every onScroll. This makes it more likely that, in Fabric,
+    // when JS processes the scroll event, the C++ ShadowNode representation will have a
+    // "more correct" scroll position. It will frequently be /incorrect/ but this decreases
+    // the error as much as possible.
+    updateFabricScrollState(scrollView);
+    emitScrollEvent(scrollView, xVelocity, yVelocity);
+  }
+
   public static <
           T extends
               ViewGroup & FabricViewStateManager.HasFabricViewStateManager & HasScrollState
@@ -491,7 +505,7 @@ public void onAnimationStart(Animator animator) {
               @Override
               public void onAnimationEnd(Animator animator) {
                 scrollView.getReactScrollViewScrollState().setIsFinished(true);
-                ReactScrollViewHelper.updateStateOnScroll(scrollView);
+                updateFabricScrollState(scrollView);
               }
 
               @Override