Don't add duplicated line box rects into focus ring rects

Source/core/layout/LayoutBlock.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2007 David Smith (catfish.man@gmail.com)
  * Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011 Apple Inc. All rights reserved.
  * Copyright (C) Research In Motion Limited 2010. All rights reserved.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
@@ skipping 3529 matching lines @@
             LayoutUnit top = std::max<LayoutUnit>(curr->lineTop(), curr->top());
             LayoutUnit bottom = std::min<LayoutUnit>(curr->lineBottom(), curr->top() + curr->height());
             LayoutRect rect(additionalOffset.x() + curr->x(), additionalOffset.y() + top, curr->width(), bottom - top);
             if (!rect.isEmpty())
                 rects.append(rect);
         }
 
         addChildFocusRingRects(rects, additionalOffset);
     }
 
-    if (inlineElementContinuation)
-        inlineElementContinuation->addFocusRingRects(rects, additionalOffset + (inlineElementContinuation->containingBlock()->location() - location()));
+    if (inlineElementContinuation) {
+        Vector<LayoutRect> inlineFocusRingRects;
+        // We need to give the LayoutInline a clean vector to let it add focus ring rects of line boxes.
+        inlineElementContinuation->addFocusRingRects(inlineFocusRingRects, additionalOffset + (inlineElementContinuation->containingBlock()->location() - location()));
+        rects.appendVector(inlineFocusRingRects);
+    }
 }
 
 void LayoutBlock::computeSelfHitTestRects(Vector<LayoutRect>& rects, const LayoutPoint& layerOffset) const
 {
     LayoutBox::computeSelfHitTestRects(rects, layerOffset);
 
     if (hasHorizontalLayoutOverflow() || hasVerticalLayoutOverflow()) {
         for (RootInlineBox* curr = firstRootBox(); curr; curr = curr->nextRootBox()) {
             LayoutUnit top = std::max<LayoutUnit>(curr->lineTop(), curr->top());
             LayoutUnit bottom = std::min<LayoutUnit>(curr->lineBottom(), curr->top() + curr->height());
@@ skipping 349 matching lines @@
 void LayoutBlock::showLineTreeAndMark(const InlineBox* markedBox1, const char* markedLabel1, const InlineBox* markedBox2, const char* markedLabel2, const LayoutObject* obj) const
 {
     showLayoutObject();
     for (const RootInlineBox* root = firstRootBox(); root; root = root->nextRootBox())
         root->showLineTreeAndMark(markedBox1, markedLabel1, markedBox2, markedLabel2, obj, 1);
 }
 
 #endif
 
 } // namespace blink