Turn zone_excess_limit_ into a constant.

src/zone.cc

 // 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 50 matching lines @@
   Address address(int n) const {
     return Address(this) + n;
   }
 
   Segment* next_;
   int size_;
 };
 
 
 Zone::Zone(Isolate* isolate)
-    : zone_excess_limit_(256 * MB),
-      allocation_size_(0),
+    : allocation_size_(0),
       segment_bytes_allocated_(0),
       position_(0),
       limit_(0),
       segment_head_(NULL),
       isolate_(isolate) {
 }
 
 
 Zone::~Zone() {
 #ifdef DEBUG
@@ skipping 87 matching lines @@
     V8::FatalProcessOutOfMemory("Zone");
     return NULL;
   }
   limit_ = segment->end();
   ASSERT(position_ <= limit_);
   return result;
 }
 
 
 } }  // namespace v8::internal