Fix RTL scroll bars being misrendered on Android.

Source/core/platform/ScrollbarThemeOverlay.cpp

Index: Source/core/platform/ScrollbarThemeOverlay.cpp
diff --git a/Source/core/platform/ScrollbarThemeOverlay.cpp b/Source/core/platform/ScrollbarThemeOverlay.cpp
index b1869343acb6b453a5806ca89b66656b6b71d39f..97151de64a3f143f79b6d396b1d74dc73d11bb99 100644
--- a/Source/core/platform/ScrollbarThemeOverlay.cpp
+++ b/Source/core/platform/ScrollbarThemeOverlay.cpp
@@ -107,10 +107,13 @@ IntRect ScrollbarThemeOverlay::trackRect(ScrollbarThemeClient* scrollbar, bool)
 void ScrollbarThemeOverlay::paintThumb(GraphicsContext* context, ScrollbarThemeClient* scrollbar, const IntRect& rect)
 {
     IntRect thumbRect = rect;
-    if (scrollbar->orientation() == HorizontalScrollbar)
+    if (scrollbar->orientation() == HorizontalScrollbar) {
         thumbRect.setHeight(thumbRect.height() - m_scrollbarMargin);
-    else
+    } else {
         thumbRect.setWidth(thumbRect.width() - m_scrollbarMargin);
+        if (scrollbar->isLeftSideVerticalScrollbar())
+            thumbRect.setX(thumbRect.x() + m_scrollbarMargin);
+    }
     context->fillRect(thumbRect, m_color);
 }