Oilpan: move RenderObjects off heap.

Source/core/rendering/RenderBlock.cpp

Index: Source/core/rendering/RenderBlock.cpp
diff --git a/Source/core/rendering/RenderBlock.cpp b/Source/core/rendering/RenderBlock.cpp
index ba9413e84b2bd82202614b5fe17c04509a9d98ed..e5402221ac9cd1966960a12f6e4cd4f402a833e0 100644
--- a/Source/core/rendering/RenderBlock.cpp
+++ b/Source/core/rendering/RenderBlock.cpp
@@ -158,12 +158,6 @@ RenderBlock::RenderBlock(ContainerNode* node)
     // By default, subclasses do not have inline children.
 }
 
-void RenderBlock::trace(Visitor* visitor)
-{
-    visitor->trace(m_children);
-    RenderBox::trace(visitor);
-}
-
 static void removeBlockFromDescendantAndContainerMaps(RenderBlock* block, TrackedDescendantsMap*& descendantMap, TrackedContainerMap*& containerMap)
 {
     if (OwnPtr<TrackedRendererListHashSet> descendantSet = descendantMap->take(block)) {
@@ -226,18 +220,7 @@ void RenderBlock::removeFromGlobalMaps()
 
 RenderBlock::~RenderBlock()
 {
-#if !ENABLE(OILPAN)
     removeFromGlobalMaps();
-#endif
-}
-
-void RenderBlock::destroy()
-{
-    RenderBox::destroy();
-#if ENABLE(OILPAN)
-    // RenderObject::removeChild called in destory() depends on gColumnInfoMap.
-    removeFromGlobalMaps();
-#endif
 }
 
 void RenderBlock::willBeDestroyed()