Fix overflow rect calculation for float in rtl container.

third_party/WebKit/Source/core/layout/LayoutBlockFlow.h

Index: third_party/WebKit/Source/core/layout/LayoutBlockFlow.h
diff --git a/third_party/WebKit/Source/core/layout/LayoutBlockFlow.h b/third_party/WebKit/Source/core/layout/LayoutBlockFlow.h
index c6d4d711d83ad29ffc61d08f1915c46f6089ed7f..ecc82710c737c1dde65884cbf6f5d4460d93076d 100644
--- a/third_party/WebKit/Source/core/layout/LayoutBlockFlow.h
+++ b/third_party/WebKit/Source/core/layout/LayoutBlockFlow.h
@@ -327,9 +327,11 @@ class CORE_EXPORT LayoutBlockFlow : public LayoutBlock {
 
   LayoutUnit xPositionForFloatIncludingMargin(
       const FloatingObject& child) const {
-    if (isHorizontalWritingMode())
-      return child.x() + child.layoutObject()->marginLeft();
-
+    LayoutUnit scrollbarAdjustment(originAdjustmentForScrollbars().width());
+    if (isHorizontalWritingMode()) {
+      return child.x() + child.layoutObject()->marginLeft() +
+             scrollbarAdjustment;
+    }
     return child.x() + marginBeforeForChild(*child.layoutObject());
   }