Revert of Oilpan: Implement a GC to take a heap snapshot

Source/platform/heap/Heap.h

Index: Source/platform/heap/Heap.h
diff --git a/Source/platform/heap/Heap.h b/Source/platform/heap/Heap.h
index e659551b04ef9f10ab7afe3e3f02724244d64677..2365632741e4b20576cf2db71237d027adc48395 100644
--- a/Source/platform/heap/Heap.h
+++ b/Source/platform/heap/Heap.h
@@ -430,6 +430,7 @@
 
     void markAsUnswept()
     {
+        ASSERT(m_swept);
         m_swept = false;
     }
 
@@ -691,7 +692,7 @@
 #endif
 
     virtual void clearFreeLists() { }
-    void makeConsistentForSweeping(ThreadState::GCType);
+    void makeConsistentForSweeping();
 #if ENABLE(ASSERT)
     virtual bool isConsistentForSweeping() = 0;
 #endif
@@ -923,7 +924,7 @@
     static void globalWeakProcessing(Visitor*);
     static void setForcePreciseGCForTesting();
 
-    static void preGC(ThreadState::GCType);
+    static void preGC();
     static void postGC(ThreadState::GCType);
 
     // Conservatively checks whether an address is a pointer in any of the