[New Multicolumn] Let updatePagination() do its job also when composited.

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 ae55488a0722593747264efa0e4a7efb84fdc24b..72927f747eaa3cbb064ecbe7a27e48a7b8828313 100644
--- a/Source/core/rendering/RenderLayer.cpp
+++ b/Source/core/rendering/RenderLayer.cpp
@@ -473,9 +473,9 @@ void RenderLayer::updatePaginationRecursive(bool needsPaginationUpdate)
 
 void RenderLayer::updatePagination()
 {
-    if (compositingState() != NotComposited || !parent())
-        return; // FIXME: We will have to deal with paginated compositing layers someday.
-                // FIXME: For now the RenderView can't be paginated.  Eventually printing will move to a model where it is though.
+    bool regionBasedColumnsUsed = useRegionBasedColumns();

[Julien - ping for review, 2014/10/20 15:52:36]

Style: boolean should have a conjugated verb in them so it should be
isRegionBasedColumnUsed or to match the caller better usesRegionBasedColumn.

[mstensho (USE GERRIT), 2014/10/20 18:54:31]

Done.

+    if ((!regionBasedColumnsUsed && compositingState() != NotComposited) || !parent())
+        return; // FIXME: For now the RenderView can't be paginated.  Eventually printing will move to a model where it is though.
 
     // The main difference between the paginated booleans for the old column code and the new column code
     // is that each paginated layer has to paint on its own with the new code. There is no
@@ -484,7 +484,6 @@ void RenderLayer::updatePagination()
     // genuinely know if it is going to have to split itself up when painting only its contents (and not any other descendant
     // layers). We track an enclosingPaginationLayer instead of using a simple bit, since we want to be able to get back
     // to that layer easily.
-    bool regionBasedColumnsUsed = useRegionBasedColumns();
     if (regionBasedColumnsUsed && renderer()->isRenderFlowThread()) {
         m_enclosingPaginationLayer = this;
         return;