Remove heap protection support.

src/heap.h

 // Copyright 2011 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 391 matching lines @@
   Address* NewSpaceAllocationTopAddress() {
     return new_space_.allocation_top_address();
   }
   Address* NewSpaceAllocationLimitAddress() {
     return new_space_.allocation_limit_address();
   }
 
   // Uncommit unused semi space.
   bool UncommitFromSpace() { return new_space_.UncommitFromSpace(); }
 
-#ifdef ENABLE_HEAP_PROTECTION
-  // Protect/unprotect the heap by marking all spaces read-only/writable.
-  void Protect();
-  void Unprotect();
-#endif
-
   // Allocates and initializes a new JavaScript object based on a
   // constructor.
   // Returns Failure::RetryAfterGC(requested_bytes, space) if the allocation
   // failed.
   // Please note this does not perform a garbage collection.
   MUST_USE_RESULT MaybeObject* AllocateJSObject(
       JSFunction* constructor, PretenureFlag pretenure = NOT_TENURED);
 
   // Allocates and initializes a new global object based on a constructor.
   // Returns Failure::RetryAfterGC(requested_bytes, space) if the allocation
@@ skipping 1872 matching lines @@
   DISALLOW_IMPLICIT_CONSTRUCTORS(PathTracer);
 };
 #endif  // DEBUG || LIVE_OBJECT_LIST
 
 
 } }  // namespace v8::internal
 
 #undef HEAP
 
 #endif  // V8_HEAP_H_