Remove ThreadHeap::m_threads

third_party/WebKit/Source/platform/heap/Heap.h

Index: third_party/WebKit/Source/platform/heap/Heap.h
diff --git a/third_party/WebKit/Source/platform/heap/Heap.h b/third_party/WebKit/Source/platform/heap/Heap.h
index e9b3b88085121ebe0acad3b511b427edf94255c5..bf5ebe7337f5c468fa878425bc6c4bd5e16b4d60 100644
--- a/third_party/WebKit/Source/platform/heap/Heap.h
+++ b/third_party/WebKit/Source/platform/heap/Heap.h
@@ -220,11 +220,9 @@ class ThreadHeapStats {
   double m_estimatedMarkingTimePerByte;
 };
 
-using ThreadStateSet = HashSet<ThreadState*>;
-
 class PLATFORM_EXPORT ThreadHeap {
  public:
-  ThreadHeap();
+  explicit ThreadHeap(ThreadState*);
   ~ThreadHeap();
 
   // Returns true for main thread's heap.
@@ -270,8 +268,6 @@ class PLATFORM_EXPORT ThreadHeap {
 
   StackFrameDepth& stackFrameDepth() { return m_stackFrameDepth; }
 
-  RecursiveMutex& threadAttachMutex() { return m_threadAttachMutex; }
-  const ThreadStateSet& threads() const { return m_threads; }
   ThreadHeapStats& heapStats() { return m_stats; }
   CallbackStack* markingStack() const { return m_markingStack.get(); }
   CallbackStack* postMarkingCallbackStack() const {
@@ -282,11 +278,6 @@ class PLATFORM_EXPORT ThreadHeap {
   }
   CallbackStack* ephemeronStack() const { return m_ephemeronStack.get(); }
 
-  void attach(ThreadState*);
-  void detach(ThreadState*);
-  void lockThreadAttachMutex();
-  void unlockThreadAttachMutex();
-
   void visitPersistentRoots(Visitor*);
   void visitStackRoots(Visitor*);
   void enterSafePoint(ThreadState*);
@@ -454,8 +445,7 @@ class PLATFORM_EXPORT ThreadHeap {
   void commitCallbackStacks();
   void decommitCallbackStacks();
 
-  RecursiveMutex m_threadAttachMutex;
-  ThreadStateSet m_threads;
+  ThreadState* m_threadState;
   ThreadHeapStats m_stats;
   std::unique_ptr<RegionTree> m_regionTree;
   std::unique_ptr<HeapDoesNotContainCache> m_heapDoesNotContainCache;