Remove the dependency of Zone on Isolate

src/lithium-allocator.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/v8.h"
 
 #include "src/hydrogen.h"
 #include "src/lithium-inl.h"
 #include "src/lithium-allocator-inl.h"
 #include "src/string-stream.h"
@@ skipping 493 matching lines @@
       AdvanceLastProcessedMarker(a, advance_last_processed_up_to);
     } else {
       b = b->next();
     }
   }
   return LifetimePosition::Invalid();
 }
 
 
 LAllocator::LAllocator(int num_values, HGraph* graph)
-    : zone_(graph->isolate()),
-      chunk_(NULL),
+    : chunk_(NULL),
       live_in_sets_(graph->blocks()->length(), zone()),
       live_ranges_(num_values * 2, zone()),
       fixed_live_ranges_(NULL),
       fixed_double_live_ranges_(NULL),
       unhandled_live_ranges_(num_values * 2, zone()),
       active_live_ranges_(8, zone()),
       inactive_live_ranges_(8, zone()),
       reusable_slots_(8, zone()),
       next_virtual_register_(num_values),
       first_artificial_register_(num_values),
@@ skipping 1659 matching lines @@
     isolate()->GetHTracer()->TraceLiveRanges(name(), allocator_);
   }
 
 #ifdef DEBUG
   if (allocator_ != NULL) allocator_->Verify();
 #endif
 }
 
 
 } }  // namespace v8::internal