[RAL] Make sure RenderLayers are invalidated when moved.

Source/core/rendering/RenderLayer.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 245 matching lines @@
 {
     TRACE_EVENT0("blink_rendering", "RenderLayer::updateLayerPositionsAfterLayout");
 
     // FIXME: Remove incremental compositing updates after fixing the chicken/egg issues
     // https://code.google.com/p/chromium/issues/detail?id=343756
     DisableCompositingQueryAsserts disabler;
 
     RenderGeometryMap geometryMap(UseTransforms);
     if (this != rootLayer)
         geometryMap.pushMappingsToAncestor(parent(), 0);
-    updateLayerPositions(&geometryMap, flags);
+    updateLayerPositions(&geometryMap, rootLayer->renderer()->containerForRepaint(), flags);
 }
 
-void RenderLayer::updateLayerPositions(RenderGeometryMap* geometryMap, UpdateLayerPositionsFlags flags)
+void RenderLayer::updateLayerPositions(RenderGeometryMap* geometryMap, const RenderLayerModelObject* paintInvalidationContainer, UpdateLayerPositionsFlags flags)
 {
     updateLayerPosition(); // For relpositioned layers or non-positioned layers,
                            // we need to keep in sync, since we may have shifted relative
                            // to our parent layer.
     if (geometryMap)
         geometryMap->pushMappingsToAncestor(this, parent());
 
     // Clear our cached clip rect information.
     m_clipper.clearClipRects();
 
@@ skipping 11 matching lines @@
 
     updateDescendantDependentFlags();
 
     if (flags & UpdatePagination)
         updatePagination();
     else {
         m_isPaginated = false;
         m_enclosingPaginationLayer = 0;
     }
 
+    const RenderLayerModelObject* newPaintInvalidationContainer = paintInvalidationContainer;
+    if (RuntimeEnabledFeatures::repaintAfterLayoutEnabled()) {
+        bool establishesNewPaintInvalidationContainer = isRepaintContainer();
+        newPaintInvalidationContainer = renderer()->adjustCompositedContainerForSpecialAncestors(establishesNewPaintInvalidationContainer ? renderer() : paintInvalidationContainer);
+
+        if (geometryMap) {
+            LayoutPoint offset = renderer()->isBox() ? toRenderBox(renderer())->location() : LayoutPoint();
+            if (renderer()->previousPositionFromPaintInvalidationContainer() != geometryMap->mapToContainer(offset, newPaintInvalidationContainer))
+                renderer()->setMayNeedPaintInvalidation(true);

[leviw_travelin_and_unemployed, 2014/06/02 20:47:21]

I still don't love this We're only okay because we're guaranteed to do a full
walk with a RenderGeometryMap, right? We don't really need to update the
repaintContainer in the other cases, I just wish we had a way to enforce that we
get into this code in the full-walk case we need it in.

I'd recommend assigning paintInvalidationContainer to null when we don't have a
geometry map to document where/how this is used and to avoid the unnecessary
work in other cases, and maybe add a comment about the reason we can gate the
code on having a geometryMap.

[dsinclair, 2014/06/02 20:58:07]

Done. Is this better?

+        }
+    }
+
     repainter().repaintAfterLayout(flags & CheckForRepaint);
 
     // Go ahead and update the reflection's position and size.
     if (m_reflectionInfo)
         m_reflectionInfo->reflection()->layout();
 
     if (useRegionBasedColumns() && renderer()->isRenderFlowThread()) {
         updatePagination();
         flags |= UpdatePagination;
     }
 
     if (renderer()->hasColumns())
         flags |= UpdatePagination;
 
     for (RenderLayer* child = firstChild(); child; child = child->nextSibling())
-        child->updateLayerPositions(geometryMap, flags);
+        child->updateLayerPositions(geometryMap, newPaintInvalidationContainer, flags);
 
     if ((flags & NeedsFullRepaintInBacking) && hasCompositedLayerMapping() && !compositedLayerMapping()->paintsIntoCompositedAncestor())
         compositedLayerMapping()->setContentsNeedDisplay();
 
     if (geometryMap)
         geometryMap->popMappingsToAncestor(parent());
 }
 
 void RenderLayer::setAncestorChainHasSelfPaintingLayerDescendant()
 {
@@ skipping 1149 matching lines @@
         m_parent->addChild(current, nextSib);
 
         if (RuntimeEnabledFeatures::repaintAfterLayoutEnabled())
             current->renderer()->setShouldDoFullPaintInvalidationAfterLayout(true);
         else
             current->repainter().setRepaintStatus(NeedsFullRepaint);
 
         // Hits in compositing/overflow/automatically-opt-into-composited-scrolling-part-1.html
         DisableCompositingQueryAsserts disabler;
 
-        current->updateLayerPositions(0); // FIXME: use geometry map.
+        current->updateLayerPositions(0, 0); // FIXME: use geometry map.
         current = next;
     }
 
     // Remove us from the parent.
     m_parent->removeChild(this);
     m_renderer->destroyLayer();
 }
 
 void RenderLayer::insertOnlyThisLayer()
 {
@@ skipping 2430 matching lines @@
     }
 }
 
 void showLayerTree(const WebCore::RenderObject* renderer)
 {
     if (!renderer)
         return;
     showLayerTree(renderer->enclosingLayer());
 }
 #endif