[RAL] Make sure RenderLayers are invalidated when moved.

Source/core/rendering/RenderBlock.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2007 David Smith (catfish.man@gmail.com)
  * Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011 Apple Inc. All rights reserved.
  * Copyright (C) Research In Motion Limited 2010. 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 347 matching lines @@
     Vector<ImageResource*> images;
     appendImagesFromStyle(images, *newStyle);
     if (images.isEmpty())
         ResourceLoadPriorityOptimizer::resourceLoadPriorityOptimizer()->removeRenderObject(this);
     else
         ResourceLoadPriorityOptimizer::resourceLoadPriorityOptimizer()->addRenderObject(this);
 }
 
 void RenderBlock::repaintTreeAfterLayout(const RenderLayerModelObject& repaintContainer)
 {
-    if (!shouldCheckForInvalidationAfterLayout())
-        return;
+    // Note, we don't want to early out here using shouldCheckForInvalidationAfterLayout as
+    // we have to make sure we go through any positioned objects as they won't be seen in
+    // the normal tree walk.
 
     RenderBox::repaintTreeAfterLayout(repaintContainer);

[ojan, 2014/05/24 05:14:29]

Can this be: 
if (shouldCheckForInvalidationAfterLayout())
    RenderBox::repaintTreeAfterLayout(repaintContainer);

If it can't, then the comment is not quite sufficient as it only talks about
positioned objects.

[dsinclair, 2014/05/26 14:57:25]

Done. I didn't bother before since the RenderBox version has the same check but
this saves us calling the repaintTreeAfterLayout method at all.

 
     // Take care of positioned objects. This is required as LayoutState keeps a single clip rect.
     if (TrackedRendererListHashSet* positionedObjects = this->positionedObjects()) {
         TrackedRendererListHashSet::iterator end = positionedObjects->end();
         LayoutStateMaintainer statePusher(*this, isTableRow() ? LayoutSize() : locationOffset());
         for (TrackedRendererListHashSet::iterator it = positionedObjects->begin(); it != end; ++it) {
             RenderBox* box = *it;
 
             // One of the renderers we're skipping over here may be the child's repaint container,
             // so we can't pass our own repaint container along.
             const RenderLayerModelObject& repaintContainerForChild = *box->containerForRepaint();
 
+            // When a floating object is moved the children do not get layout but they get a new position.
+            // We have to make sure we invalidate the children if a floating parent container moves.
+            if (isFloating() || isRelPositioned()) {
+                if (box->previousPositionFromRepaintContainer() != box->positionFromRepaintContainer(&repaintContainerForChild)) {
+                    // Note, this has to be non-recursive. If we walk up the tree we'll end up setting
+                    // the flag on our parent who has already cleared their flags for this invalidation
+                    // walk. We also don't have to force them to walk as we're all ready there.
+                    box->setMayNeedInvalidationNonRecursive(true);
+                }
+            }
+
             // If the positioned renderer is absolutely positioned and it is inside
             // a relatively positioend inline element, we need to account for
             // the inline elements position in LayoutState.
             if (box->style()->position() == AbsolutePosition) {
                 RenderObject* container = box->container(&repaintContainerForChild, 0);
                 if (container->isInFlowPositioned() && container->isRenderInline()) {
                     // FIXME: We should be able to use layout-state for this.
                     // Currently, we will place absolutly positioned elements inside
                     // relatively positioned inline blocks in the wrong location. crbug.com/371485
                     LayoutStateDisabler disable(*this);
@@ skipping 4623 matching lines @@
 void RenderBlock::showLineTreeAndMark(const InlineBox* markedBox1, const char* markedLabel1, const InlineBox* markedBox2, const char* markedLabel2, const RenderObject* obj) const
 {
     showRenderObject();
     for (const RootInlineBox* root = firstRootBox(); root; root = root->nextRootBox())
         root->showLineTreeAndMark(markedBox1, markedLabel1, markedBox2, markedLabel2, obj, 1);
 }
 
 #endif
 
 } // namespace WebCore