Do not greedy GC if no allocation is expected/allowed.

R=dcarney@chromium.org

Review URL: https://codereview.chromium.org/227513003

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@20548 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/heap.cc

@@ -7528,6 +7528,7 @@ void Heap::GarbageCollectionGreedyCheck() {
   ASSERT(FLAG_gc_greedy);
   if (isolate_->bootstrapper()->IsActive()) return;
   if (!AllowAllocationFailure::IsAllowed(isolate_)) return;
+  if (!AllowHeapAllocation::IsAllowed(isolate_)) return;
   CollectGarbage(NEW_SPACE);
 }
 #endif