Fix a bunch of spelling mistakes :\

src/zone.h

 // Copyright 2006-2008 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 99 matching lines @@
 
 
 // ZoneObject is an abstraction that helps define classes of objects
 // allocated in the Zone. Use it as a base class; see ast.h.
 class ZoneObject {
  public:
   // Allocate a new ZoneObject of 'size' bytes in the Zone.
   void* operator new(size_t size) { return Zone::New(size); }
 
   // Ideally, the delete operator should be private instead of
-  // public, but unfortuately the compiler sometimes synthesizes
+  // public, but unfortunately the compiler sometimes synthesizes
   // (unused) destructors for classes derived from ZoneObject, which
   // require the operator to be visible. MSVC requires the delete
   // operator to be public.
 
   // ZoneObjects should never be deleted individually; use
   // Zone::DeleteAll() to delete all zone objects in one go.
   void operator delete(void*, size_t) { UNREACHABLE(); }
 };
 
 
@@ skipping 60 matching lines @@
 
  private:
   ZoneScopeMode mode_;
   static int nesting_;
 };
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_ZONE_H_