Oilpan: Reduce sizeof(Persistent) to 16 byte

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 4280ad1be9e53457a725d65cc657686e302b583c..7f27c9e3d1ea0c939a6db36b2c095e7bae8c1ae9 100644
--- a/Source/platform/heap/ThreadState.h
+++ b/Source/platform/heap/ThreadState.h
@@ -52,12 +52,13 @@ namespace blink {
 
 class BasePage;
 class CallbackStack;
+class CrossThreadPersistentRegion;
 struct GCInfo;
 class GarbageCollectedMixinConstructorMarker;
 class HeapObjectHeader;
 class PageMemoryRegion;
 class PageMemory;
-class PersistentAnchor;
+class PersistentRegion;
 class BaseHeap;
 class SafePointAwareMutexLocker;
 class SafePointBarrier;
@@ -473,12 +474,11 @@ public:
 #endif
 
     // List of persistent roots allocated on the given thread.
-    PersistentAnchor* roots() const { return m_persistents.get(); }
+    PersistentRegion* persistentRegion() const { return m_persistentRegion.get(); }
 
     // List of global persistent roots not owned by any particular thread.
     // globalRootsMutex must be acquired before any modifications.

[sof, 2015/06/30 09:19:39]

Comment still mentions globalRootsMutex.

[haraken, 2015/06/30 09:51:32]

Done.

-    static PersistentAnchor& globalRoots();
-    static Mutex& globalRootsMutex();
+    static CrossThreadPersistentRegion& crossThreadPersistentRegion();
 
     // Visit local thread stack and trace all pointers conservatively.
     void visitStack(Visitor*);
@@ -733,7 +733,7 @@ private:
     static uint8_t s_mainThreadStateStorage[];
 
     ThreadIdentifier m_thread;
-    OwnPtr<PersistentAnchor> m_persistents;
+    OwnPtr<PersistentRegion> m_persistentRegion;
     StackState m_stackState;
     intptr_t* m_startOfStack;
     intptr_t* m_endOfStack;