Add checks for per thread heap

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 40482db58d209521ff8e441509afa93a356ac2cb..42256b33d4d725d82d0d933137d720549ec5588d 100644
--- a/third_party/WebKit/Source/platform/heap/Heap.h
+++ b/third_party/WebKit/Source/platform/heap/Heap.h
@@ -202,6 +202,11 @@ public:
         // always 'alive'.
         if (!object)
             return true;
+        // TODO(keishi): some tests create CrossThreadPersistent on non attached threads.
+        if (!ThreadState::current())
+            return true;
+        if (&ThreadState::current()->heap() != &pageFromObject(object)->arena()->getThreadState()->heap())
+            return true;

[haraken, 2016/05/26 07:52:29]

Hmm, you still have this code?

[keishi, 2016/05/26 11:52:54]

Sorry, probably made a mistake with git.

I've changed it to a DCHECK so developers using isHeapObjectAlive in
clearWeakMembers will notice if they use it on a cross thread object.

         return ObjectAliveTrait<T>::isHeapObjectAlive(object);
     }
     template<typename T>