Fix pixel snapping issues when layers become composited

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 9a2f22bd0b135fdf9a775c82a38b7cdbf21340ab..1f0c362a9035c0b2bdca141264d8e792e89cdf66 100644
--- a/Source/core/rendering/RenderLayerCompositor.cpp
+++ b/Source/core/rendering/RenderLayerCompositor.cpp
@@ -493,7 +493,7 @@ void RenderLayerCompositor::logLayerInfo(const RenderLayer* layer, int depth)
     layerName = layer->debugName();
 #endif
 
-    LOG(Compositing, "%*p %dx%d %.2fKB (%s) %s\n", 12 + depth * 2, layer, backing->compositedBounds().width(), backing->compositedBounds().height(),
+    LOG(Compositing, "%*p %dx%d %.2fKB (%s) %s\n", 12 + depth * 2, layer, backing->compositedBounds().width().round(), backing->compositedBounds().height().round(),

[eae, 2013/07/26 20:30:51]

Why not log the precise values?

[leviw_travelin_and_unemployed, 2013/07/26 20:36:21]

Good question :)

         backing->backingStoreMemoryEstimate() / 1024,
         logReasonsForCompositing(layer), layerName.utf8().data());
 }
@@ -638,10 +638,10 @@ void RenderLayerCompositor::repaintInCompositedAncestor(RenderLayer* layer, cons
 
 // The bounds of the GraphicsLayer created for a compositing layer is the union of the bounds of all the descendant
 // RenderLayers that are rendered by the composited RenderLayer.
-IntRect RenderLayerCompositor::calculateCompositedBounds(const RenderLayer* layer, const RenderLayer* ancestorLayer) const
+LayoutRect RenderLayerCompositor::calculateCompositedBounds(const RenderLayer* layer, const RenderLayer* ancestorLayer) const
 {
     if (!canBeComposited(layer))
-        return IntRect();
+        return LayoutRect();
 
     RenderLayer::CalculateLayerBoundsFlags flags = RenderLayer::DefaultCalculateLayerBoundsFlags | RenderLayer::ExcludeHiddenDescendants | RenderLayer::DontConstrainForMask;
 #if HAVE(COMPOSITOR_FILTER_OUTSETS)