[debugger] do not enable liveedit by default.

src/debug/debug-interface.h

 // Copyright 2016 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_DEBUG_DEBUG_INTERFACE_H_
 #define V8_DEBUG_DEBUG_INTERFACE_H_
 
 #include <functional>
 
 #include "include/v8-debug.h"
@@ skipping 43 matching lines @@
  */
 // TODO(dcarney): data arg should be a MaybeLocal
 MaybeLocal<Value> Call(Local<Context> context, v8::Local<v8::Function> fun,
                        Local<Value> data = Local<Value>());
 
 /**
  * Enable/disable LiveEdit functionality for the given Isolate
  * (default Isolate if not provided). V8 will abort if LiveEdit is
  * unexpectedly used. LiveEdit is enabled by default.
  */
-void SetLiveEditEnabled(Isolate* isolate, bool enable);
+V8_EXPORT_PRIVATE void SetLiveEditEnabled(Isolate* isolate, bool enable);
 
 // Schedule a debugger break to happen when JavaScript code is run
 // in the given isolate.
 void DebugBreak(Isolate* isolate);
 
 // Remove scheduled debugger break in given isolate if it has not
 // happened yet.
 void CancelDebugBreak(Isolate* isolate);
 
 /**
@@ skipping 180 matching lines @@
   ~Coverage();
 
  private:
   explicit Coverage(i::Coverage* coverage) : coverage_(coverage) {}
   i::Coverage* coverage_;
 };
 }  // namespace debug
 }  // namespace v8
 
 #endif  // V8_DEBUG_DEBUG_INTERFACE_H_