Remove heap protection support.

src/vm-state-inl.h

 // Copyright 2010 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 51 matching lines @@
 VMState::VMState(Isolate* isolate, StateTag tag)
     : isolate_(isolate), previous_tag_(isolate->current_vm_state()) {
 #ifdef ENABLE_LOGGING_AND_PROFILING
   if (FLAG_log_state_changes) {
     LOG(isolate, UncheckedStringEvent("Entering", StateToString(tag)));
     LOG(isolate, UncheckedStringEvent("From", StateToString(previous_tag_)));
   }
 #endif
 
   isolate_->SetCurrentVMState(tag);
-
-#ifdef ENABLE_HEAP_PROTECTION
-  if (FLAG_protect_heap) {
-    if (tag == EXTERNAL) {
-      // We are leaving V8.
-      ASSERT(previous_tag_ != EXTERNAL);
-      isolate_->heap()->Protect();
-    } else if (previous_tag_ = EXTERNAL) {
-      // We are entering V8.
-      isolate_->heap()->Unprotect();
-    }
-  }
-#endif
 }
 
 
 VMState::~VMState() {
 #ifdef ENABLE_LOGGING_AND_PROFILING
   if (FLAG_log_state_changes) {
     LOG(isolate_,
         UncheckedStringEvent("Leaving",
                               StateToString(isolate_->current_vm_state())));
     LOG(isolate_,
         UncheckedStringEvent("To", StateToString(previous_tag_)));
   }
 #endif  // ENABLE_LOGGING_AND_PROFILING
 
-#ifdef ENABLE_HEAP_PROTECTION
-  StateTag tag = isolate_->current_vm_state();
-#endif
-
   isolate_->SetCurrentVMState(previous_tag_);
-
-#ifdef ENABLE_HEAP_PROTECTION
-  if (FLAG_protect_heap) {
-    if (tag == EXTERNAL) {
-      // We are reentering V8.
-      ASSERT(previous_tag_ != EXTERNAL);
-      isolate_->heap()->Unprotect();
-    } else if (previous_tag_ == EXTERNAL) {
-      // We are leaving V8.
-      isolate_->heap()->Protect();
-    }
-  }
-#endif  // ENABLE_HEAP_PROTECTION
 }
 
 #endif  // ENABLE_VMSTATE_TRACKING
 
 
 #ifdef ENABLE_LOGGING_AND_PROFILING
 
 ExternalCallbackScope::ExternalCallbackScope(Isolate* isolate, Address callback)
     : isolate_(isolate), previous_callback_(isolate->external_callback()) {
   isolate_->set_external_callback(callback);
 }
 
 ExternalCallbackScope::~ExternalCallbackScope() {
   isolate_->set_external_callback(previous_callback_);
 }
 
 #endif  // ENABLE_LOGGING_AND_PROFILING
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_VM_STATE_INL_H_