Delete RCTFloorPixelValue

Summary:
This is dead code. Let's remove this for now.

This api is unsafe: if it's called from a non-ui thread, it may dispatch to the ui thread synchronously.

Changelog: [iOS][Removed] - Remove RCTFloorPixelValue

Reviewed By: NickGerleman

Differential Revision: D72260694

fbshipit-source-id: d032917643c957a395ee380ef925a047abd5dace

Author: RSNara

packages/react-native/React/Base/RCTUtils.h

@@ -58,7 +58,6 @@ RCT_EXTERN CGSize RCTViewportSize(void);
 // Round float coordinates to nearest whole screen pixel (not point)
 RCT_EXTERN CGFloat RCTRoundPixelValue(CGFloat value);
 RCT_EXTERN CGFloat RCTCeilPixelValue(CGFloat value);
-RCT_EXTERN CGFloat RCTFloorPixelValue(CGFloat value);
 
 // Convert a size in points to pixels, rounded up to the nearest integral size
 RCT_EXTERN CGSize RCTSizeInPixels(CGSize pointSize, CGFloat scale);

packages/react-native/React/Base/RCTUtils.m

@@ -395,12 +395,6 @@ CGFloat RCTCeilPixelValue(CGFloat value)
   return ceil(value * scale) / scale;
 }
 
-CGFloat RCTFloorPixelValue(CGFloat value)
-{
-  CGFloat scale = RCTScreenScale();
-  return floor(value * scale) / scale;
-}
-
 CGSize RCTSizeInPixels(CGSize pointSize, CGFloat scale)
 {
   return (CGSize){