Use unified invalidation path for repaint-only style changes

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 1544 matching lines @@
     ASSERT(!needsLayout());
 
     if (!shouldCheckForPaintInvalidation())
         return;
 
     bool establishesNewPaintInvalidationContainer = isPaintInvalidationContainer();
     const RenderLayerModelObject& newPaintInvalidationContainer = *adjustCompositedContainerForSpecialAncestors(establishesNewPaintInvalidationContainer ? this : &paintInvalidationState.paintInvalidationContainer());
     // FIXME: This assert should be re-enabled when we move paint invalidation to after compositing update. crbug.com/360286
     // ASSERT(&newPaintInvalidationContainer == containerForPaintInvalidation());
 
+    invalidatePaintIfNeeded(paintInvalidationState, newPaintInvalidationContainer);
+
+    // This is for the next invalidatePaintIfNeeded so must be after invalidatePaintIfNeeded().
+    savePreviousBorderBoxSizeIfNeeded();
+
+    PaintInvalidationState childTreeWalkState(paintInvalidationState, *this, newPaintInvalidationContainer);
+    RenderObject::invalidateTreeIfNeeded(childTreeWalkState);
+}
+
+void RenderBox::invalidatePaintIfNeeded(const PaintInvalidationState& paintInvalidationState, const RenderLayerModelObject& newPaintInvalidationContainer)
+{
+    if (!shouldCheckForSelfPaintInvalidation())
+        return;
+
     const LayoutRect oldPaintInvalidationRect = previousPaintInvalidationRect();
     const LayoutPoint oldPositionFromPaintInvalidationContainer = previousPositionFromPaintInvalidationContainer();
     setPreviousPaintInvalidationRect(boundsRectForPaintInvalidation(&newPaintInvalidationContainer, &paintInvalidationState));
     setPreviousPositionFromPaintInvalidationContainer(RenderLayer::positionFromPaintInvalidationContainer(this, &newPaintInvalidationContainer, &paintInvalidationState));
 
     // If we are set to do a full paint invalidation that means the RenderView will be
     // issue paint invalidations. We can then skip issuing of paint invalidations for the child
     // renderers as they'll be covered by the RenderView.
-    if (view()->doingFullRepaint()) {
-        PaintInvalidationState childTreeWalkState(paintInvalidationState, *this, newPaintInvalidationContainer);
-        RenderObject::invalidateTreeIfNeeded(childTreeWalkState);
-        // For the next invalidatePaintIfNeeded.
-        savePreviousBorderBoxSizeIfNeeded();

[dsinclair, 2014/07/17 18:36:01]

Does the ordering of these two methods matter? In the old version we invalidated
children and then savePreviousBorderBoxSizeIfNeeded().

In the new version we do the opposite.

[Xianzhu, 2014/07/17 21:57:34]

They are actually equivalent. There were two calls to
savePreviousBorderBoxSizeIfNeeded(). This one was needed because of the early
return. I extracted the logic invalidating the object itself into the new
invalidatePaintIfNeeded to avoid the duplicated code in early returns. 

+    if (view()->doingFullRepaint())
         return;
-    }
 
     if ((onlyNeededPositionedMovementLayout() && compositingState() != PaintsIntoOwnBacking)
         || (shouldDoFullPaintInvalidationIfSelfPaintingLayer()
             && hasLayer()
             && layer()->isSelfPaintingLayer())) {
         setShouldDoFullPaintInvalidation(true);
     }
 
-    if (!invalidatePaintIfNeeded(newPaintInvalidationContainer, oldPaintInvalidationRect, oldPositionFromPaintInvalidationContainer, paintInvalidationState))
+    if (!RenderObject::invalidatePaintIfNeeded(newPaintInvalidationContainer, oldPaintInvalidationRect, oldPositionFromPaintInvalidationContainer, paintInvalidationState))
         invalidatePaintForOverflowIfNeeded();
 
-    // This is for the next invalidatePaintIfNeeded so must be after invalidatePaintIfNeeded.
-    savePreviousBorderBoxSizeIfNeeded();
-
     // Issue paint invalidations for any scrollbars if there is a scrollable area for this renderer.
     if (enclosingLayer()) {
         if (RenderLayerScrollableArea* area = enclosingLayer()->scrollableArea()) {
             if (area->hasVerticalBarDamage())
                 invalidatePaintRectangle(area->verticalBarDamage());
             if (area->hasHorizontalBarDamage())
                 invalidatePaintRectangle(area->horizontalBarDamage());
             area->resetScrollbarDamage();
         }
     }
-
-    PaintInvalidationState childTreeWalkState(paintInvalidationState, *this, newPaintInvalidationContainer);
-    RenderObject::invalidateTreeIfNeeded(childTreeWalkState);
 }
 
 bool RenderBox::pushContentsClip(PaintInfo& paintInfo, const LayoutPoint& accumulatedOffset, ContentsClipBehavior contentsClipBehavior)
 {
     if (paintInfo.phase == PaintPhaseBlockBackground || paintInfo.phase == PaintPhaseSelfOutline || paintInfo.phase == PaintPhaseMask)
         return false;
 
     bool isControlClip = hasControlClip();
     bool isOverflowClip = hasOverflowClip() && !layer()->isSelfPaintingLayer();
 
@@ skipping 3008 matching lines @@
 
         // We need the old border box size only when the box has background or box decorations.
         if (!style()->hasBackground() && !style()->hasBoxDecorations())
             return;
     }
 
     ensureRareData().m_previousBorderBoxSize = size();
 }
 
 } // namespace WebCore