Initialise LineMeasurement::xHeight in constructor

Summary:
Fix a bug in the constructor of `LineMeasurement` where it did not initialise `xHeight` correctly.

Changelog: [Internal]

Reviewed By: JoshuaGross

Differential Revision: D27972942

fbshipit-source-id: a56d55fdfe286bd11a6a81a3d024504f070bdb19

ReactCommon/react/renderer/textlayoutmanager/TextMeasureCache.cpp

@@ -34,7 +34,8 @@ LineMeasurement::LineMeasurement(
       frame(frame),
       descender(descender),
       capHeight(capHeight),
-      ascender(ascender) {}
+      ascender(ascender),
+      xHeight(xHeight) {}
 
 LineMeasurement::LineMeasurement(folly::dynamic const &data)
     : text(data.getDefault("text", "").getString()),