To ensure consistency between layouts, we need to reset any overriden top for centering the textfie…

Source/core/rendering/RenderTextControlSingleLine.cpp

 /**
  * Copyright (C) 2006, 2007, 2010 Apple Inc. All rights reserved.
  *           (C) 2008 Torch Mobile Inc. All rights reserved. (http://www.torchmobile.com/)
  * Copyright (C) 2010 Google Inc. All rights reserved.
  * Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies).
  *
  * 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
  * version 2 of the License, or (at your option) any later version.
@@ skipping 91 matching lines @@
     //   intrinsic heights of the inner elements.
 
     // We don't honor paddings and borders for textfields without decorations
     // and type=search if the text height is taller than the contentHeight()
     // because of compability.
 
     RenderBox* innerEditorRenderer = innerEditorElement()->renderBox();
     RenderBox* viewPortRenderer = editingViewPortElement() ? editingViewPortElement()->renderBox() : 0;
 
     // To ensure consistency between layouts, we need to reset any conditionally overriden height.
-    if (innerEditorRenderer && !innerEditorRenderer->style()->logicalHeight().isAuto()) {
-        innerEditorRenderer->style()->setLogicalHeight(Length(Auto));
+    if (innerEditorRenderer) {

[Julien - ping for review, 2014/11/11 16:57:58]

This will be forcing a relayout of the innerEditorRenderer *all the time*.
That's super heavy and there should be a way to handle that better. Maybe
switching to the overrideLogicalHeight would help?

[pals, 2014/11/12 13:29:08]

I have moved to a flag which is set when center the textfield. The logicalTop
keeps accumulating overriden value in case of simplifiedLayout while centering
the innerEditor.

+        if (!innerEditorRenderer->style()->logicalHeight().isAuto())
+            innerEditorRenderer->style()->setLogicalHeight(Length(Auto));
         layoutScope.setNeedsLayout(innerEditorRenderer);
         HTMLElement* placeholderElement = inputElement()->placeholderElement();
         if (RenderBox* placeholderBox = placeholderElement ? placeholderElement->renderBox() : 0)
             layoutScope.setNeedsLayout(placeholderBox);
     }
     if (viewPortRenderer && !viewPortRenderer->style()->logicalHeight().isAuto()) {
         viewPortRenderer->style()->setLogicalHeight(Length(Auto));
         layoutScope.setNeedsLayout(viewPortRenderer);
     }
 
@@ skipping 288 matching lines @@
     if (innerEditorElement())
         innerEditorElement()->setScrollTop(newTop);
 }
 
 HTMLInputElement* RenderTextControlSingleLine::inputElement() const
 {
     return toHTMLInputElement(node());
 }
 
 }