Make squashing work with subpixel layout

Source/core/rendering/RenderLayerCompositor.cpp

Index: Source/core/rendering/RenderLayerCompositor.cpp
diff --git a/Source/core/rendering/RenderLayerCompositor.cpp b/Source/core/rendering/RenderLayerCompositor.cpp
index 0f7daf4090606791c18d46cc295d95f4976d5924..d1fdf5f02611d6b63142615de341196a1cbd2e29 100644
--- a/Source/core/rendering/RenderLayerCompositor.cpp
+++ b/Source/core/rendering/RenderLayerCompositor.cpp
@@ -1043,7 +1043,7 @@ void RenderLayerCompositor::computeCompositingRequirements(RenderLayer* ancestor
         overlapMap->geometryMap().popMappingsToAncestor(ancestorLayer);
 }
 
-void RenderLayerCompositor::SquashingState::updateSquashingStateForNewMapping(CompositedLayerMappingPtr newCompositedLayerMapping, bool hasNewCompositedLayerMapping, IntPoint newOffsetFromAbsoluteForSquashingCLM)
+void RenderLayerCompositor::SquashingState::updateSquashingStateForNewMapping(CompositedLayerMappingPtr newCompositedLayerMapping, bool hasNewCompositedLayerMapping, LayoutPoint newOffsetFromAbsoluteForSquashingCLM)
 {
     // The most recent backing is done accumulating any more squashing layers.
     if (hasMostRecentMapping)
@@ -1055,12 +1055,12 @@ void RenderLayerCompositor::SquashingState::updateSquashingStateForNewMapping(Co
     offsetFromAbsoluteForSquashingCLM = newOffsetFromAbsoluteForSquashingCLM;
 }
 
-static IntPoint computeOffsetFromAbsolute(RenderLayer* layer)
+static LayoutPoint computeOffsetFromAbsolute(RenderLayer* layer)
 {
     TransformState transformState(TransformState::ApplyTransformDirection, FloatPoint());
     layer->renderer()->mapLocalToContainer(0, transformState, ApplyContainerFlip);
     transformState.flatten();
-    return roundedIntPoint(transformState.lastPlanarPoint());
+    return roundedLayoutPoint(transformState.lastPlanarPoint());
 }
 
 void RenderLayerCompositor::assignLayersToBackings(RenderLayer* updateRoot, bool& layersChanged)
@@ -1090,9 +1090,9 @@ void RenderLayerCompositor::assignLayersToBackingsInternal(RenderLayer* layer, S
             ASSERT(!layer->hasCompositedLayerMapping());
             ASSERT(squashingState.hasMostRecentMapping);
 
-            IntPoint offsetFromAbsoluteForSquashedLayer = computeOffsetFromAbsolute(layer);
+            LayoutPoint offsetFromAbsoluteForSquashedLayer = computeOffsetFromAbsolute(layer);
 
-            IntSize offsetFromSquashingCLM(offsetFromAbsoluteForSquashedLayer.x() - squashingState.offsetFromAbsoluteForSquashingCLM.x(),
+            LayoutSize offsetFromSquashingCLM(offsetFromAbsoluteForSquashedLayer.x() - squashingState.offsetFromAbsoluteForSquashingCLM.x(),
                 offsetFromAbsoluteForSquashedLayer.y() - squashingState.offsetFromAbsoluteForSquashingCLM.y());
 
             squashingState.mostRecentMapping->addRenderLayerToSquashingGraphicsLayer(layer, offsetFromSquashingCLM, squashingState.nextSquashedLayerIndex);
@@ -1138,7 +1138,7 @@ void RenderLayerCompositor::assignLayersToBackingsInternal(RenderLayer* layer, S
         // At this point, if the layer is to be "separately" composited, then its backing becomes the most recent in paint-order.
         if (layer->compositingState() == PaintsIntoOwnBacking || layer->compositingState() == HasOwnBackingButPaintsIntoAncestor) {
             ASSERT(!requiresSquashing(layer->compositingReasons()));
-            IntPoint offsetFromAbsoluteForSquashingCLM = computeOffsetFromAbsolute(layer);
+            LayoutPoint offsetFromAbsoluteForSquashingCLM = computeOffsetFromAbsolute(layer);
             squashingState.updateSquashingStateForNewMapping(layer->compositedLayerMapping(), layer->hasCompositedLayerMapping(), offsetFromAbsoluteForSquashingCLM);
         }
     }