Deprecate old code aging mechanism.

src/objects-visiting-inl.h

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 588 matching lines @@
 
 template<typename StaticVisitor>
 bool StaticMarkingVisitor<StaticVisitor>::IsFlushable(
     Heap* heap, JSFunction* function) {
   SharedFunctionInfo* shared_info = function->shared();
 
   // Code is either on stack, in compilation cache or referenced
   // by optimized version of function.
   MarkBit code_mark = Marking::MarkBitFrom(function->code());
   if (code_mark.Get()) {
-    if (!FLAG_age_code) {
-      if (!Marking::MarkBitFrom(shared_info).Get()) {
-        shared_info->set_code_age(0);
-      }
-    }
     return false;
   }
 
   // The function must have a valid context and not be a builtin.
   if (!IsValidNonBuiltinContext(function->unchecked_context())) {
     return false;
   }
 
   // We do not (yet) flush code for optimized functions.
   if (function->code() != shared_info->code()) {
@@ skipping 51 matching lines @@
   if (shared_info->is_toplevel()) {
     return false;
   }
 
   // If this is a function initialized with %SetCode then the one-to-one
   // relation between SharedFunctionInfo and Code is broken.
   if (shared_info->dont_flush()) {
     return false;
   }
 
-  if (FLAG_age_code) {
-    return shared_info->code()->IsOld();
-  } else {
-    // How many collections newly compiled code object will survive before being
-    // flushed.
-    static const int kCodeAgeThreshold = 5;
+  // Check age of code. If code aging is disabled we never flush.
+  if (!FLAG_age_code || !shared_info->code()->IsOld()) {
+    return false;
+  }
 
-    // Age this shared function info.
-    if (shared_info->code_age() < kCodeAgeThreshold) {
-      shared_info->set_code_age(shared_info->code_age() + 1);
-      return false;
-    }
-    return true;
-  }
+  return true;
 }
 
 
 template<typename StaticVisitor>
 void StaticMarkingVisitor<StaticVisitor>::VisitSharedFunctionInfoStrongCode(
     Heap* heap, HeapObject* object) {
   StaticVisitor::BeforeVisitingSharedFunctionInfo(object);
   Object** start_slot =
       HeapObject::RawField(object,
                            SharedFunctionInfo::BodyDescriptor::kStartOffset);
@@ skipping 121 matching lines @@
   RelocIterator it(this, mode_mask);
   for (; !it.done(); it.next()) {
     it.rinfo()->template Visit<StaticVisitor>(heap);
   }
 }
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_OBJECTS_VISITING_INL_H_