[RAL] Make sure RenderLayers are invalidated when moved.

Source/core/rendering/RenderLayer.cpp

Index: Source/core/rendering/RenderLayer.cpp
diff --git a/Source/core/rendering/RenderLayer.cpp b/Source/core/rendering/RenderLayer.cpp
index 7bd8417f0019b02aed0ba7758bb3c7a29c4cc216..b9c2e7610b2b7bf138c51c4fd2a01aafc5f28d1e 100644
--- a/Source/core/rendering/RenderLayer.cpp
+++ b/Source/core/rendering/RenderLayer.cpp
@@ -270,10 +270,10 @@ void RenderLayer::updateLayerPositionsAfterLayout(const RenderLayer* rootLayer,
     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& repaintContainer, UpdateLayerPositionsFlags flags)
 {
     updateLayerPosition(); // For relpositioned layers or non-positioned layers,
                            // we need to keep in sync, since we may have shifted relative
@@ -305,6 +305,14 @@ void RenderLayer::updateLayerPositions(RenderGeometryMap* geometryMap, UpdateLay
         m_enclosingPaginationLayer = 0;
     }
 
+    const RenderLayerModelObject* newRepaintContainer = &repaintContainer;
+    if (RuntimeEnabledFeatures::repaintAfterLayoutEnabled()) {
+        bool establishesNewRepaintContainer = isRepaintContainer();
+        newRepaintContainer = renderer()->adjustCompositedContainerForSpecialAncestors(establishesNewRepaintContainer ? renderer() : &repaintContainer);
+        if (renderer()->previousPositionFromRepaintContainer() != renderer()->positionFromRepaintContainer(newRepaintContainer))

[leviw_travelin_and_unemployed, 2014/05/28 20:51:55]

This is unfortunate duplicate work. positionFromRepaintContainer will still walk
up to the repaintContainer to determine the new offset, and later we'll do this
work again.

Taking a look at this, the real magic we should use is to backpack on the
geometryMap we're already passing along here. See
RenderGeometryMap::mapToContainer.

[leviw_travelin_and_unemployed, 2014/05/28 21:02:00]

Dan pointed out at RenderGeometryMap uses a FloatPoint, not a LayoutPoint. It
won't be quite as trivial to use it as I'd hoped, though it could be made to
work.

[dsinclair, 2014/06/02 18:14:34]

Done.

+            renderer()->setMayNeedInvalidation(true);
+    }
+
     repainter().repaintAfterLayout(flags & CheckForRepaint);
 
     // Go ahead and update the reflection's position and size.
@@ -320,7 +328,7 @@ void RenderLayer::updateLayerPositions(RenderGeometryMap* geometryMap, UpdateLay
         flags |= UpdatePagination;
 
     for (RenderLayer* child = firstChild(); child; child = child->nextSibling())
-        child->updateLayerPositions(geometryMap, flags);
+        child->updateLayerPositions(geometryMap, *newRepaintContainer, flags);
 
     if ((flags & NeedsFullRepaintInBacking) && hasCompositedLayerMapping() && !compositedLayerMapping()->paintsIntoCompositedAncestor())
         compositedLayerMapping()->setContentsNeedDisplay();
@@ -1529,7 +1537,7 @@ void RenderLayer::removeOnlyThisLayer()
         // Hits in compositing/overflow/automatically-opt-into-composited-scrolling-part-1.html
         DisableCompositingQueryAsserts disabler;
 
-        current->updateLayerPositions(0); // FIXME: use geometry map.
+        current->updateLayerPositions(0, *renderer()->containerForRepaint()); // FIXME: use geometry map.
         current = next;
     }