Get rid of ZoneScope completely.

src/hydrogen-environment-liveness.cc

 // Copyright 2013 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 19 matching lines @@
 
 
 namespace v8 {
 namespace internal {
 
 
 EnvironmentSlotLivenessAnalyzer::EnvironmentSlotLivenessAnalyzer(
     HGraph* graph)
     : graph_(graph),
       zone_(graph->isolate()),
-      zone_scope_(&zone_),
       block_count_(graph->blocks()->length()),
       maximum_environment_size_(graph->maximum_environment_size()),
       collect_markers_(true),
       last_simulate_(NULL) {
   if (maximum_environment_size_ == 0) return;
 
   live_at_block_start_ =
       new(zone()) ZoneList<BitVector*>(block_count_, zone());
   first_simulate_ = new(zone()) ZoneList<HSimulate*>(block_count_, zone());
   first_simulate_invalid_for_index_ =
@@ skipping 207 matching lines @@
     ZapEnvironmentSlotsInSuccessors(block, live);
   }
 
   // Finally, remove the HEnvironment{Bind,Lookup} markers.
   for (int i = 0; i < markers_->length(); ++i) {
     markers_->at(i)->DeleteAndReplaceWith(NULL);
   }
 }
 
 } }  // namespace v8::internal