Fix RTL scroll bars being misrendered on Android.

Source/core/platform/ScrollbarTheme.cpp

Index: Source/core/platform/ScrollbarTheme.cpp
diff --git a/Source/core/platform/ScrollbarTheme.cpp b/Source/core/platform/ScrollbarTheme.cpp
index 80b53fa528ecb9a67a1efed04521f937b2504aeb..419ab9df51efd60126334bc54a8a00e28044f8b1 100644
--- a/Source/core/platform/ScrollbarTheme.cpp
+++ b/Source/core/platform/ScrollbarTheme.cpp
@@ -208,14 +208,13 @@ void ScrollbarTheme::splitTrack(ScrollbarThemeClient* scrollbar, const IntRect&
     // This function won't even get called unless we're big enough to have some combination of these three rects where at least
     // one of them is non-empty.
     IntRect trackRect = constrainTrackRectToTrackPieces(scrollbar, unconstrainedTrackRect);
-    int thickness = scrollbar->orientation() == HorizontalScrollbar ? scrollbar->height() : scrollbar->width();
     int thumbPos = thumbPosition(scrollbar);
     if (scrollbar->orientation() == HorizontalScrollbar) {
-        thumbRect = IntRect(trackRect.x() + thumbPos, trackRect.y() + (trackRect.height() - thickness) / 2, thumbLength(scrollbar), thickness);
+        thumbRect = IntRect(trackRect.x() + thumbPos, trackRect.y(), thumbLength(scrollbar), scrollbar->height());
         beforeThumbRect = IntRect(trackRect.x(), trackRect.y(), thumbPos + thumbRect.width() / 2, trackRect.height());
         afterThumbRect = IntRect(trackRect.x() + beforeThumbRect.width(), trackRect.y(), trackRect.maxX() - beforeThumbRect.maxX(), trackRect.height());
     } else {
-        thumbRect = IntRect(trackRect.x() + (trackRect.width() - thickness) / 2, trackRect.y() + thumbPos, thickness, thumbLength(scrollbar));
+        thumbRect = IntRect(trackRect.x(), trackRect.y() + thumbPos, scrollbar->width(), thumbLength(scrollbar));
         beforeThumbRect = IntRect(trackRect.x(), trackRect.y(), trackRect.width(), thumbPos + thumbRect.height() / 2);
         afterThumbRect = IntRect(trackRect.x(), trackRect.y() + beforeThumbRect.height(), trackRect.width(), trackRect.maxY() - beforeThumbRect.maxY());
     }