Cursor to be centrally aligned instead of top aligned

Source/core/rendering/RenderBoxModelObject.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2005 Allan Sandfeld Jensen (kde@carewolf.com)
  *           (C) 2005, 2006 Samuel Weinig (sam.weinig@gmail.com)
  * Copyright (C) 2005, 2006, 2007, 2008, 2009 Apple Inc. All rights reserved.
  * Copyright (C) 2010 Google Inc. 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
@@ skipping 2543 matching lines @@
 
 LayoutRect RenderBoxModelObject::localCaretRectForEmptyElement(LayoutUnit width, LayoutUnit textIndentOffset)
 {
     ASSERT(!slowFirstChild());
 
     // FIXME: This does not take into account either :first-line or :first-letter
     // However, as soon as some content is entered, the line boxes will be
     // constructed and this kludge is not called any more. So only the caret size
     // of an empty :first-line'd block is wrong. I think we can live with that.
     RenderStyle* currentStyle = firstLineStyle();
-    LayoutUnit height = style()->fontMetrics().height();
 
     enum CaretAlignment { alignLeft, alignRight, alignCenter };
 
     CaretAlignment alignment = alignLeft;
 
     switch (currentStyle->textAlign()) {
     case LEFT:
     case WEBKIT_LEFT:
         break;
     case CENTER:
@@ skipping 31 matching lines @@
             x -= textIndentOffset / 2;
         break;
     case alignRight:
         x = maxX - caretWidth;
         if (!currentStyle->isLeftToRightDirection())
             x -= textIndentOffset;
         break;
     }
     x = std::min(x, std::max<LayoutUnit>(maxX - caretWidth, 0));
 
-    LayoutUnit y = paddingTop() + borderTop();
-
+    LayoutUnit height = style()->fontMetrics().height();
+    LayoutUnit verticalSpace = lineHeight(true, currentStyle->isHorizontalWritingMode() ? HorizontalLine : VerticalLine,  PositionOfInteriorLineBoxes) - height;
+    LayoutUnit y = paddingTop() + borderTop() + (verticalSpace / 2);
     return currentStyle->isHorizontalWritingMode() ? LayoutRect(x, y, caretWidth, height) : LayoutRect(y, x, height, caretWidth);
 }
 
 bool RenderBoxModelObject::shouldAntialiasLines(GraphicsContext* context)
 {
     // FIXME: We may want to not antialias when scaled by an integral value,
     // and we may want to antialias when translated by a non-integral value.
     // FIXME: See crbug.com/382491. getCTM does not include scale factors applied at raster time, such
     // as device zoom.
     return !context->getCTM().isIdentityOrTranslationOrFlipped();
@@ skipping 96 matching lines @@
     ASSERT(!beforeChild || toBoxModelObject == beforeChild->parent());
     for (RenderObject* child = startChild; child && child != endChild; ) {
         // Save our next sibling as moveChildTo will clear it.
         RenderObject* nextSibling = child->nextSibling();
         moveChildTo(toBoxModelObject, child, beforeChild, fullRemoveInsert);
         child = nextSibling;
     }
 }
 
 } // namespace blink