[heap] Simplify clearing of normalized map caches.

src/heap/heap.cc

Index: src/heap/heap.cc
diff --git a/src/heap/heap.cc b/src/heap/heap.cc
index 16d7f36c550f1e03109ea63e1bc53a376c279a14..20564482c8a764ab1045e02037fa919e1f7cb2ec 100644
--- a/src/heap/heap.cc
+++ b/src/heap/heap.cc
@@ -1249,26 +1249,6 @@ void Heap::EnsureFromSpaceIsCommitted() {
 }
 
 
-void Heap::ClearNormalizedMapCaches() {
-  if (isolate_->bootstrapper()->IsActive() &&

[ulan, 2017/03/13 14:36:01]

I don't understand the intent of this condition. We don't clear the caches if
the bootstrapper is active and we're doing full GC.

This is going to change to clearing unconditionally.

-      !incremental_marking()->IsMarking()) {
-    return;
-  }
-
-  Object* context = native_contexts_list();
-  while (!context->IsUndefined(isolate())) {
-    // GC can happen when the context is not fully initialized,
-    // so the cache can be undefined.
-    Object* cache =
-        Context::cast(context)->get(Context::NORMALIZED_MAP_CACHE_INDEX);
-    if (!cache->IsUndefined(isolate())) {
-      NormalizedMapCache::cast(cache)->Clear();
-    }
-    context = Context::cast(context)->next_context_link();
-  }
-}
-
-
 void Heap::UpdateSurvivalStatistics(int start_new_space_size) {
   if (start_new_space_size == 0) return;
 
@@ -1510,7 +1490,6 @@ void Heap::MarkCompactPrologue() {
   CompletelyClearInstanceofCache();
 
   FlushNumberStringCache();
-  ClearNormalizedMapCaches();
 }