Remove more feature in product mode

runtime/vm/heap.cc

Index: runtime/vm/heap.cc
diff --git a/runtime/vm/heap.cc b/runtime/vm/heap.cc
index 04ca4f7c252ea062b1fe9de84339e390e4f0d48b..d7846a7f5a557ebf1c26020fedf5e0ed24abe9f8 100644
--- a/runtime/vm/heap.cc
+++ b/runtime/vm/heap.cc
@@ -362,9 +362,11 @@ void Heap::CollectNewSpaceGarbage(Thread* thread,
     bool invoke_api_callbacks = (api_callbacks == kInvokeApiCallbacks);
     RecordBeforeGC(kNew, reason);
     VMTagScope tagScope(thread, VMTag::kGCNewSpaceTagId);
+#ifndef PRODUCT
     TimelineDurationScope tds(thread,
                               isolate()->GetGCStream(),
                               "CollectNewGeneration");
+#endif  // !PRODUCT
     UpdateClassHeapStatsBeforeGC(kNew);
     new_space_.Scavenge(invoke_api_callbacks);
     isolate()->class_table()->UpdatePromoted();
@@ -387,9 +389,11 @@ void Heap::CollectOldSpaceGarbage(Thread* thread,
     bool invoke_api_callbacks = (api_callbacks == kInvokeApiCallbacks);
     RecordBeforeGC(kOld, reason);
     VMTagScope tagScope(thread, VMTag::kGCOldSpaceTagId);
+#ifndef PRODUCT
     TimelineDurationScope tds(thread,
                               isolate()->GetGCStream(),
                               "CollectOldGeneration");
+#endif  // !PRODUCT
     UpdateClassHeapStatsBeforeGC(kOld);
     old_space_.MarkSweep(invoke_api_callbacks);
     RecordAfterGC(kOld);