[inspector] introduced stepIntoAsync for chained callbacks

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 73 matching lines @@
 void ChangeBreakOnException(Isolate* isolate, ExceptionBreakState state);
 
 enum StepAction {
   StepOut = 0,   // Step out of the current function.
   StepNext = 1,  // Step to the next statement in the current function.
   StepIn = 2     // Step into new functions invoked or the next statement
                  // in the current function.
 };
 
 void PrepareStep(Isolate* isolate, StepAction action);
+void ClearStepping(Isolate* isolate);
 
 bool HasNonBlackboxedFrameOnStack(Isolate* isolate);
 
 /**
  * Out-of-memory callback function.
  * The function is invoked when the heap size is close to the hard limit.
  *
  * \param data the parameter provided during callback installation.
  */
 typedef void (*OutOfMemoryCallback)(void* data);
@@ skipping 68 matching lines @@
 
 void SetDebugDelegate(Isolate* isolate, DebugDelegate* listener);
 
 void ResetBlackboxedStateCache(Isolate* isolate,
                                v8::Local<debug::Script> script);
 
 }  // namespace debug
 }  // namespace v8
 
 #endif  // V8_DEBUG_DEBUG_INTERFACE_H_