Don't use TLS for space iterators.

src/runtime.cc

Index: src/runtime.cc
diff --git a/src/runtime.cc b/src/runtime.cc
index f808d1060cf4a4b7c00b5a6b47685742bcd76e6b..bc2681bc87717e406d5d54beaadfe244e5d04c23 100644
--- a/src/runtime.cc
+++ b/src/runtime.cc
@@ -12446,29 +12446,30 @@ RUNTIME_FUNCTION(MaybeObject*, Runtime_DebugReferencedBy) {
 
   // Get the number of referencing objects.
   int count;
-  HeapIterator heap_iterator;
+  Heap* heap = isolate->heap();
+  HeapIterator heap_iterator(heap);
   count = DebugReferencedBy(&heap_iterator,
                             target, instance_filter, max_references,
                             NULL, 0, arguments_function);
 
   // Allocate an array to hold the result.
   Object* object;
-  { MaybeObject* maybe_object = isolate->heap()->AllocateFixedArray(count);
+  { MaybeObject* maybe_object = heap->AllocateFixedArray(count);
     if (!maybe_object->ToObject(&object)) return maybe_object;
   }
   FixedArray* instances = FixedArray::cast(object);
 
   // Fill the referencing objects.
   // AllocateFixedArray above does not make the heap non-iterable.
-  ASSERT(HEAP->IsHeapIterable());
-  HeapIterator heap_iterator2;
+  ASSERT(heap->IsHeapIterable());
+  HeapIterator heap_iterator2(heap);
   count = DebugReferencedBy(&heap_iterator2,
                             target, instance_filter, max_references,
                             instances, count, arguments_function);
 
   // Return result as JS array.
   Object* result;
-  MaybeObject* maybe_result = isolate->heap()->AllocateJSObject(
+  MaybeObject* maybe_result = heap->AllocateJSObject(
       isolate->context()->native_context()->array_function());
   if (!maybe_result->ToObject(&result)) return maybe_result;
   return JSArray::cast(result)->SetContent(instances);
@@ -12514,8 +12515,8 @@ RUNTIME_FUNCTION(MaybeObject*, Runtime_DebugConstructedBy) {
   ASSERT(args.length() == 2);
 
   // First perform a full GC in order to avoid dead objects.
-  isolate->heap()->CollectAllGarbage(Heap::kMakeHeapIterableMask,
-                                     "%DebugConstructedBy");
+  Heap* heap = isolate->heap();
+  heap->CollectAllGarbage(Heap::kMakeHeapIterableMask, "%DebugConstructedBy");
 
   // Check parameters.
   CONVERT_ARG_CHECKED(JSFunction, constructor, 0);
@@ -12524,7 +12525,7 @@ RUNTIME_FUNCTION(MaybeObject*, Runtime_DebugConstructedBy) {
 
   // Get the number of referencing objects.
   int count;
-  HeapIterator heap_iterator;
+  HeapIterator heap_iterator(heap);
   count = DebugConstructedBy(&heap_iterator,
                              constructor,
                              max_references,
@@ -12533,14 +12534,14 @@ RUNTIME_FUNCTION(MaybeObject*, Runtime_DebugConstructedBy) {
 
   // Allocate an array to hold the result.
   Object* object;
-  { MaybeObject* maybe_object = isolate->heap()->AllocateFixedArray(count);
+  { MaybeObject* maybe_object = heap->AllocateFixedArray(count);
     if (!maybe_object->ToObject(&object)) return maybe_object;
   }
   FixedArray* instances = FixedArray::cast(object);
 
   ASSERT(HEAP->IsHeapIterable());
   // Fill the referencing objects.
-  HeapIterator heap_iterator2;
+  HeapIterator heap_iterator2(heap);
   count = DebugConstructedBy(&heap_iterator2,
                              constructor,
                              max_references,
@@ -12550,7 +12551,7 @@ RUNTIME_FUNCTION(MaybeObject*, Runtime_DebugConstructedBy) {
   // Return result as JS array.
   Object* result;
   { MaybeObject* maybe_result = isolate->heap()->AllocateJSObject(
-          isolate->context()->native_context()->array_function());
+      isolate->context()->native_context()->array_function());
     if (!maybe_result->ToObject(&result)) return maybe_result;
   }
   return JSArray::cast(result)->SetContent(instances);
@@ -12677,19 +12678,20 @@ RUNTIME_FUNCTION(MaybeObject*,
   Handle<FixedArray> array;
   array = isolate->factory()->NewFixedArray(kBufferSize);
   int number;
+  Heap* heap = isolate->heap();
   {
-    isolate->heap()->EnsureHeapIsIterable();
+    heap->EnsureHeapIsIterable();
     AssertNoAllocation no_allocations;
-    HeapIterator heap_iterator;
+    HeapIterator heap_iterator(heap);
     Script* scr = *script;
     FixedArray* arr = *array;
     number = FindSharedFunctionInfosForScript(&heap_iterator, scr, arr);
   }
   if (number > kBufferSize) {
     array = isolate->factory()->NewFixedArray(number);
-    isolate->heap()->EnsureHeapIsIterable();
+    heap->EnsureHeapIsIterable();
     AssertNoAllocation no_allocations;
-    HeapIterator heap_iterator;
+    HeapIterator heap_iterator(heap);
     Script* scr = *script;
     FixedArray* arr = *array;
     FindSharedFunctionInfosForScript(&heap_iterator, scr, arr);
@@ -13026,9 +13028,10 @@ static Handle<Object> Runtime_GetScriptFromScriptName(
   // Scan the heap for Script objects to find the script with the requested
   // script data.
   Handle<Script> script;
-  script_name->GetHeap()->EnsureHeapIsIterable();
+  Heap* heap = script_name->GetHeap();
+  heap->EnsureHeapIsIterable();
   AssertNoAllocation no_allocation_during_heap_iteration;
-  HeapIterator iterator;
+  HeapIterator iterator(heap);
   HeapObject* obj = NULL;
   while (script.is_null() && ((obj = iterator.next()) != NULL)) {
     // If a script is found check if it has the script data requested.