Add a dirty bit for updateDescendantDependentFlags.

Source/core/paint/DeprecatedPaintLayer.cpp

 /*
  * Copyright (C) 2006, 2007, 2008, 2009, 2010, 2011, 2012 Apple Inc. All rights reserved.
  *
  * Portions are Copyright (C) 1998 Netscape Communications Corporation.
  *
  * Other contributors:
  *   Robert O'Callahan <roc+@cs.cmu.edu>
  *   David Baron <dbaron@fas.harvard.edu>
  *   Christian Biesinger <cbiesinger@web.de>
  *   Randall Jesup <rjesup@wgate.com>
@@ skipping 633 matching lines @@
     if (!paintInvalidationContainer->groupedMapping())
         return layoutObject->computePaintInvalidationRect(paintInvalidationContainer->layoutObject(), paintInvalidationState);
 
     LayoutRect rect = layoutObject->clippedOverflowRectForPaintInvalidation(paintInvalidationContainer->layoutObject(), paintInvalidationState);
     mapRectToPaintBackingCoordinates(paintInvalidationContainer->layoutObject(), rect);
     return rect;
 }
 
 void DeprecatedPaintLayer::dirtyVisibleContentStatus()
 {
+    compositor()->setNeedsUpdateDescendantDependentFlags();
     m_visibleContentStatusDirty = true;
     if (parent())
         parent()->dirtyAncestorChainVisibleDescendantStatus();
 }
 
 void DeprecatedPaintLayer::potentiallyDirtyVisibleContentStatus(EVisibility visibility)
 {
     if (m_visibleContentStatusDirty)
         return;
     if (hasVisibleContent() == (visibility == VISIBLE))
         return;
     dirtyVisibleContentStatus();
 }
 
 void DeprecatedPaintLayer::dirtyAncestorChainVisibleDescendantStatus()
 {
+    compositor()->setNeedsUpdateDescendantDependentFlags();
+
     for (DeprecatedPaintLayer* layer = this; layer; layer = layer->parent()) {
         if (layer->m_visibleDescendantStatusDirty)
             break;
-
         layer->m_visibleDescendantStatusDirty = true;
     }
 }
 
 // FIXME: this is quite brute-force. We could be more efficient if we were to
 // track state and update it as appropriate as changes are made in the layout tree.
 void DeprecatedPaintLayer::updateScrollingStateAfterCompositingChange()
 {
     TRACE_EVENT0("blink", "DeprecatedPaintLayer::updateScrollingStateAfterCompositingChange");
     m_hasVisibleNonLayerContent = false;
     for (LayoutObject* r = layoutObject()->slowFirstChild(); r; r = r->nextSibling()) {
         if (!r->hasLayer()) {
             m_hasVisibleNonLayerContent = true;
             break;
         }
     }
 
     m_hasNonCompositedChild = false;
     for (DeprecatedPaintLayer* child = firstChild(); child; child = child->nextSibling()) {
         if (child->compositingState() == NotComposited) {
             m_hasNonCompositedChild = true;
             return;
         }
     }
 }
 
-// The descendant-dependent flags system is badly broken because we clean dirty
-// bits in upward tree walks, which means we need to call updateDescendantDependentFlags
-// at every node in the tree to fully clean all the dirty bits. While we'll in
-// the process of fixing this issue, updateDescendantDependentFlagsForEntireSubtree
-// provides a big hammer for actually cleaning all the dirty bits in a subtree.
-//
-// FIXME: Remove this function once the descendant-dependent flags system keeps
-// its dirty bits scoped to subtrees.
-void DeprecatedPaintLayer::updateDescendantDependentFlagsForEntireSubtree()
-{
-    updateDescendantDependentFlags();
-
-    for (DeprecatedPaintLayer* child = firstChild(); child; child = child->nextSibling())
-        child->updateDescendantDependentFlagsForEntireSubtree();
-}
-
 void DeprecatedPaintLayer::updateDescendantDependentFlags()
 {
     if (m_visibleDescendantStatusDirty) {
         m_hasVisibleDescendant = false;
 
         for (DeprecatedPaintLayer* child = firstChild(); child; child = child->nextSibling()) {
             child->updateDescendantDependentFlags();
 
             if (child->m_hasVisibleContent || child->m_hasVisibleDescendant) {
                 m_hasVisibleDescendant = true;
@@ skipping 2253 matching lines @@
 
 void showLayerTree(const blink::LayoutObject* layoutObject)
 {
     if (!layoutObject) {
         fprintf(stderr, "Cannot showLayerTree. Root is (nil)\n");
         return;
     }
     showLayerTree(layoutObject->enclosingLayer());
 }
 #endif