Replace RenderArena with PartitionAlloc.

Source/core/platform/Partitions.h

Index: Source/core/platform/Partitions.h
diff --git a/Source/core/platform/Task.h b/Source/core/platform/Partitions.h
similarity index 78%
copy from Source/core/platform/Task.h
copy to Source/core/platform/Partitions.h
index b9d2e46802aebf6391df4ec3dabb580d43b2483c..fe2d148e031293c783516666cae8f5d6c16266f1 100644
--- a/Source/core/platform/Task.h
+++ b/Source/core/platform/Partitions.h
@@ -28,30 +28,26 @@
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
-#ifndef Task_h
-#define Task_h
+#ifndef Partitions_h
+#define Partitions_h
 
-#include "wtf/Functional.h"
-#include "public/platform/WebThread.h"
+#include "wtf/PartitionAlloc.h"
 
 namespace WebCore {
 
-class Task : public WebKit::WebThread::Task {
+class Partitions {
 public:
-    explicit Task(const Closure& closure)
-        : m_closure(closure)
-    {
-    }
+    static void init();
+    static void shutdown();
 
-    virtual void run() OVERRIDE
-    {
-        m_closure();
-    }
+    ALWAYS_INLINE static PartitionRoot* getObjectModelPartition() { return &m_objectModelRoot; }
+    ALWAYS_INLINE static PartitionRoot* getRenderingPartition() { return &m_renderingRoot; }
 
 private:
-    Closure m_closure;
+    static PartitionRoot m_objectModelRoot;
+    static PartitionRoot m_renderingRoot;
 };
 
 } // namespace WebCore
 
-#endif // Task_h
+#endif // Partitions_h