Oilpan: GC profiling.

Source/platform/heap/ThreadState.h

Index: Source/platform/heap/ThreadState.h
diff --git a/Source/platform/heap/ThreadState.h b/Source/platform/heap/ThreadState.h
index 5269820c6417a1cff55af4d7d8237da95eed2fb1..df0f32fecff1a6b7b878546f8f8f38bf0bf3410a 100644
--- a/Source/platform/heap/ThreadState.h
+++ b/Source/platform/heap/ThreadState.h
@@ -33,6 +33,7 @@
 
 #include "platform/PlatformExport.h"
 #include "platform/heap/AddressSanitizer.h"
+#include "platform/heap/Profiling.h"
 #include "wtf/HashSet.h"
 #include "wtf/OwnPtr.h"
 #include "wtf/PassOwnPtr.h"
@@ -41,6 +42,10 @@
 #include "wtf/ThreadingPrimitives.h"
 #include "wtf/Vector.h"
 
+#if GC_PROFILE_HEAP
+#include "wtf/HashMap.h"
+#endif
+
 namespace WebCore {
 
 class BaseHeap;
@@ -495,11 +500,40 @@ public:
     // the object to which it points.
     bool checkAndMarkPointer(Visitor*, Address);
 
-#if ENABLE(GC_TRACING)
+#if GC_PROFILE_MARKING
     const GCInfo* findGCInfo(Address);
     static const GCInfo* findGCInfoFromAllThreads(Address);
 #endif
 
+#if GC_PROFILE_HEAP
+    struct SnapshotInfo {
+        ThreadState* state;
+
+        size_t liveSize;
+        size_t deadSize;
+        size_t freeSize;
+        size_t pageCount;
+
+        // Map from base-classes to a snapshot class-ids (used as index below).
+        HashMap<const GCInfo*, size_t> classTags;
+
+        // Map from class-id (index) to count.
+        Vector<int> liveCount;
+        Vector<int> deadCount;
+
+        // Map from class-id (index) to a vector of generation counts.
+        // For i < 7, the count is the number of objects that died after surviving |i| GCs.
+        // For i == 7, the count is the number of objects that survived at least 7 GCs.
+        Vector<Vector<int, 8> > generations;
+
+        SnapshotInfo(ThreadState* state) : state(state), liveSize(0), deadSize(0), freeSize(0), pageCount(0) { }
+
+        size_t getClassTag(const GCInfo*);
+    };
+
+    void snapshot();
+#endif
+
     void pushWeakObjectPointerCallback(void*, WeakPointerCallback);
     bool popAndInvokeWeakPointerCallback(Visitor*);