Fix text node rounding with fractional dimensions matching the rounding factor

Summary:
If we have a fractional measure output which matches the subpixel rounding factor, we still should round both dimension into the same direction.

Fixes react/yoga#580.
Closes react/yoga#583

Reviewed By: marco-cova

Differential Revision: D5274212

Pulled By: emilsjolander

fbshipit-source-id: 1febf9194210437ab77f91319d10d4da9b284b79

Author: woehrl01

ReactCommon/yoga/yoga/Yoga.c

@@ -3471,8 +3471,8 @@ static void YGRoundToPixelGrid(const YGNodeRef node,
   node->layout.position[YGEdgeTop] =
       YGRoundValueToPixelGrid(nodeTop, pointScaleFactor, false, textRounding);
 
-  const bool hasFractionalWidth = !YGFloatsEqual(fmodf(nodeWidth, 1.0), 0);
-  const bool hasFractionalHeight = !YGFloatsEqual(fmodf(nodeHeight, 1.0), 0);
+  const bool hasFractionalWidth = !YGFloatsEqual(fmodf(nodeWidth, 1 / pointScaleFactor), 0);
+  const bool hasFractionalHeight = !YGFloatsEqual(fmodf(nodeHeight, 1 / pointScaleFactor), 0);
 
   node->layout.dimensions[YGDimensionWidth] =
       YGRoundValueToPixelGrid(