Remove d8's interactive Javascript debugger.

src/d8.h

Index: src/d8.h
diff --git a/src/d8.h b/src/d8.h
index 4e217640af1b13c63d6470ec497daaa9ae1c6887..d63352e353761bc4df9bc2727b0f5500dc476a30 100644
--- a/src/d8.h
+++ b/src/d8.h
@@ -390,11 +390,6 @@ class Shell : public i::AllStatic {
   static void AddHistogramSample(void* histogram, int sample);
   static void MapCounters(v8::Isolate* isolate, const char* name);
 
-  static Local<Object> DebugMessageDetails(Isolate* isolate,
-                                           Local<String> message);
-  static Local<Value> DebugCommandToJSONRequest(Isolate* isolate,
-                                                Local<String> command);
-
   static void PerformanceNow(const v8::FunctionCallbackInfo<v8::Value>& args);
 #endif  // !V8_SHARED
 
@@ -492,7 +487,6 @@ class Shell : public i::AllStatic {
   static void InstallUtilityScript(Isolate* isolate);
 #endif  // !V8_SHARED
   static void Initialize(Isolate* isolate);
-  static void InitializeDebugger(Isolate* isolate);
   static void RunShell(Isolate* isolate);
   static bool SetOptions(int argc, char* argv[]);
   static Local<ObjectTemplate> CreateGlobalTemplate(Isolate* isolate);