[heap] Disallow allocation on the last page in address range

src/heap/spaces.h

 // Copyright 2011 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.
 
 #ifndef V8_HEAP_SPACES_H_
 #define V8_HEAP_SPACES_H_
 
 #include "src/allocation.h"
 #include "src/atomic-utils.h"
 #include "src/base/atomicops.h"
@@ skipping 1438 matching lines @@
     do {
       ptr = lowest_ever_allocated_.Value();
     } while ((low < ptr) && !lowest_ever_allocated_.TrySetValue(ptr, low));
     do {
       ptr = highest_ever_allocated_.Value();
     } while ((high > ptr) && !highest_ever_allocated_.TrySetValue(ptr, high));
   }
 
   List<MemoryChunk*> chunk_pool_;
 
+  base::VirtualMemory last_chunk_;
+
   friend class TestCodeRangeScope;
 
   DISALLOW_IMPLICIT_CONSTRUCTORS(MemoryAllocator);
 };
 
 
 // -----------------------------------------------------------------------------
 // Interface for heap object iterator to be implemented by all object space
 // object iterators.
 //
@@ skipping 1620 matching lines @@
     count = 0;
   }
   // Must be small, since an iteration is used for lookup.
   static const int kMaxComments = 64;
 };
 #endif
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_HEAP_SPACES_H_