Convert some call sites to use explicit LayoutRect->FloatRect conversion.

Source/core/layout/LayoutPart.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 2000 Simon Hausmann <hausmann@kde.org>
  *           (C) 2000 Stefan Schimanski (1Stein@gmx.de)
  * Copyright (C) 2004, 2005, 2006, 2009 Apple Inc. All rights reserved.
  * Copyright (C) Research In Motion Limited 2011. 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 279 matching lines @@
         return;
     widget->widgetPositionsUpdated();
 }
 
 bool LayoutPart::updateWidgetGeometry()
 {
     Widget* widget = this->widget();
     ASSERT(widget);
 
     LayoutRect contentBox = contentBoxRect();
-    LayoutRect absoluteContentBox(localToAbsoluteQuad(FloatQuad(contentBox)).boundingBox());
+    LayoutRect absoluteContentBox(localToAbsoluteQuad(FloatQuad(FloatRect(contentBox))).boundingBox());

[eae, 2015/08/25 17:47:17]

Might be easier to add a FloatQuad constructor that takes a LayoutRect? I'll
leave that up to you though.

[chrishtr, 2015/08/25 18:30:44]

I'd prefer not to, to make the performance more obvious to future developers.

     if (widget->isFrameView()) {
         contentBox.setLocation(absoluteContentBox.location());
         return setWidgetGeometry(contentBox);
     }
 
     return setWidgetGeometry(absoluteContentBox);
 }
 
 // Widgets are always placed on integer boundaries, so rounding the size is actually
 // the desired behavior. This function is here because it's otherwise seldom what we
@@ skipping 27 matching lines @@
     if (widget() && widget()->isFrameView()) {
         FrameView* childFrameView = toFrameView(widget());
         PaintInvalidationState childViewPaintInvalidationState(*childFrameView->layoutView(), paintInvalidationState);
         toFrameView(widget())->invalidateTreeIfNeeded(childViewPaintInvalidationState);
     }
 
     LayoutReplaced::invalidatePaintOfSubtreesIfNeeded(paintInvalidationState);
 }
 
 }