Remove obsolete comment in LayoutFlowThread::mapToVisualRectInAncestorSpace.

third_party/WebKit/Source/core/layout/LayoutFlowThread.cpp

Index: third_party/WebKit/Source/core/layout/LayoutFlowThread.cpp
diff --git a/third_party/WebKit/Source/core/layout/LayoutFlowThread.cpp b/third_party/WebKit/Source/core/layout/LayoutFlowThread.cpp
index a27ce472645453c5f4b71b62f55da6e1cffa4d20..5eae393e2aa636d4e15d5605d726220a4a2fb9e6 100644
--- a/third_party/WebKit/Source/core/layout/LayoutFlowThread.cpp
+++ b/third_party/WebKit/Source/core/layout/LayoutFlowThread.cpp
@@ -99,9 +99,6 @@ void LayoutFlowThread::validateColumnSets()
 bool LayoutFlowThread::mapToVisualRectInAncestorSpace(const LayoutBoxModelObject* ancestor, LayoutRect& rect, VisualRectFlags visualRectFlags) const
 {
     ASSERT(ancestor != this); // A flow thread should never be an invalidation container.
-    // |rect| is a layout rectangle, where the block direction coordinate is flipped for writing
-    // mode. fragmentsBoundingBox(), on the other hand, works on physical rectangles, so we need to
-    // flip the rectangle before and after calling it.
     rect = fragmentsBoundingBox(rect);
     return LayoutBlockFlow::mapToVisualRectInAncestorSpace(ancestor, rect, visualRectFlags);
 }