Turn styleWillChange |newStyle| into a reference

Source/core/rendering/RenderBox.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, 2010 Apple Inc. All rights reserved.
  * Copyright (C) 2013 Adobe Systems Incorporated. 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 119 matching lines @@
         if (parentBlockFlow) {
             parentBlockFlow->markSiblingsWithFloatsForLayout(this);
             parentBlockFlow->markAllDescendantsWithFloatsForLayout(this, false);
         }
     }
 
     if (isOutOfFlowPositioned())
         RenderBlock::removePositionedObject(this);
 }
 
-void RenderBox::styleWillChange(StyleDifference diff, const RenderStyle* newStyle)
+void RenderBox::styleWillChange(StyleDifference diff, const RenderStyle& newStyle)
 {
     RenderStyle* oldStyle = style();
     if (oldStyle) {
         // The background of the root element or the body element could propagate up to
         // the canvas.  Just dirty the entire canvas when our style changes substantially.
         if (diff >= StyleDifferenceRepaint && node() &&
             (isHTMLHtmlElement(*node()) || isHTMLBodyElement(*node()))) {
 
             if (!RuntimeEnabledFeatures::repaintAfterLayoutEnabled() || diff != StyleDifferenceLayout)
                 view()->repaint();
 
-            if (oldStyle->hasEntirelyFixedBackground() != newStyle->hasEntirelyFixedBackground())
+            if (oldStyle->hasEntirelyFixedBackground() != newStyle.hasEntirelyFixedBackground())
                 view()->compositor()->rootFixedBackgroundsChanged();
         }
 
         // When a layout hint happens and an object's position style changes, we have to do a layout
         // to dirty the render tree using the old position value now.
-        if (diff == StyleDifferenceLayout && parent() && oldStyle->position() != newStyle->position()) {
+        if (diff == StyleDifferenceLayout && parent() && oldStyle->position() != newStyle.position()) {
             markContainingBlocksForLayout();
             if (oldStyle->position() == StaticPosition)
                 repaint();
-            else if (newStyle->hasOutOfFlowPosition())
+            else if (newStyle.hasOutOfFlowPosition())
                 parent()->setChildNeedsLayout();
-            if (isFloating() && !isOutOfFlowPositioned() && newStyle->hasOutOfFlowPosition())
+            if (isFloating() && !isOutOfFlowPositioned() && newStyle.hasOutOfFlowPosition())
                 removeFloatingOrPositionedChildFromBlockLists();
         }
-    } else if (newStyle && isBody())
+    // FIXME: This branch runs when !oldStyle, which means that layout was never called
+    // so what's the point in invalidating the whole view that we never painted?

[esprehn, 2014/03/31 20:07:51]

yeah this code doesn't make any sense, you should remove it.

[Julien - ping for review, 2014/03/31 20:20:27]

I will post a follow-up patch for that to keep this change a refactoring.

+    } else if (isBody())
         view()->repaint();
 
     RenderBoxModelObject::styleWillChange(diff, newStyle);
 }
 
 void RenderBox::styleDidChange(StyleDifference diff, const RenderStyle* oldStyle)
 {
     // Horizontal writing mode definition is updated in RenderBoxModelObject::updateFromStyle,
     // (as part of the RenderBoxModelObject::styleDidChange call below). So, we can safely cache the horizontal
     // writing mode value before style change here.
@@ skipping 4483 matching lines @@
         return 0;
 
     if (!layoutState && !flowThreadContainingBlock())
         return 0;
 
     RenderBlock* containerBlock = containingBlock();
     return containerBlock->offsetFromLogicalTopOfFirstPage() + logicalTop();
 }
 
 } // namespace WebCore