Relax zone allocation assertion

runtime/vm/thread.cc

Index: runtime/vm/thread.cc
diff --git a/runtime/vm/thread.cc b/runtime/vm/thread.cc
index 42df5357d8254b55e7cc496071f723072af84082..d3534af507c72cf44fe3800a27c77b6ecaaeb426 100644
--- a/runtime/vm/thread.cc
+++ b/runtime/vm/thread.cc
@@ -21,6 +21,7 @@
 #include "vm/thread_interrupter.h"
 #include "vm/thread_registry.h"
 #include "vm/timeline.h"
+#include "vm/zone.h"
 
 namespace dart {
 
@@ -423,6 +424,19 @@ uword Thread::GetAndClearInterrupts() {
 }
 
 
+bool Thread::ZoneIsOwnedByThread(Zone* zone) const {
+  ASSERT(zone != NULL);
+  Zone* current = zone_;
+  while (current != NULL) {
+    if (current == zone) {
+      return true;
+    }
+    current = current->previous();
+  }
+  return false;
+}
+
+
 void Thread::DeferOOBMessageInterrupts() {
   MonitorLocker ml(thread_lock_);
   defer_oob_messages_count_++;