Revert r12825 and r12796 from trunk.

src/heap.cc

Index: src/heap.cc
diff --git a/src/heap.cc b/src/heap.cc
index 11bf9cd4d4a92909bc0d7b9cbc4260cf8622aaeb..32395975a221adb38896c2bd981213ca45c1a5c8 100644
--- a/src/heap.cc
+++ b/src/heap.cc
@@ -420,14 +420,6 @@ void Heap::GarbageCollectionPrologue() {
   gc_count_++;
   unflattened_strings_length_ = 0;
 
-  bool should_enable_code_flushing = FLAG_flush_code;
-#ifdef ENABLE_DEBUGGER_SUPPORT
-  if (isolate_->debug()->IsLoaded() || isolate_->debug()->has_break_points()) {
-    should_enable_code_flushing = false;
-  }
-#endif
-  mark_compact_collector()->EnableCodeFlushing(should_enable_code_flushing);
-
 #ifdef VERIFY_HEAP
   if (FLAG_verify_heap) {
     Verify();
@@ -1327,12 +1319,6 @@ void Heap::Scavenge() {
     }
   }
 
-  // Copy objects reachable from the code flushing candidates list.
-  MarkCompactCollector* collector = mark_compact_collector();
-  if (collector->is_code_flushing_enabled()) {
-    collector->code_flusher()->IteratePointersToFromSpace(&scavenge_visitor);
-  }
-
   // Scavenge object reachable from the native contexts list directly.
   scavenge_visitor.VisitPointer(BitCast<Object**>(&native_contexts_list_));
 
@@ -5548,7 +5534,6 @@ bool Heap::LookupSymbolIfExists(String* string, String** symbol) {
   return symbol_table()->LookupSymbolIfExists(string, symbol);
 }
 
-
 void Heap::ZapFromSpace() {
   NewSpacePageIterator it(new_space_.FromSpaceStart(),
                           new_space_.FromSpaceEnd());