Introduce PromiseRejectCallback.

src/debug.h

 // Copyright 2012 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_H_
 #define V8_DEBUG_H_
 
 #include "src/allocation.h"
 #include "src/arguments.h"
 #include "src/assembler.h"
@@ skipping 511 matching lines @@
   MUST_USE_RESULT MaybeHandle<Object> MakeCompileEvent(
       Handle<Script> script, v8::DebugEvent type);
   MUST_USE_RESULT MaybeHandle<Object> MakePromiseEvent(
       Handle<JSObject> promise_event);
   MUST_USE_RESULT MaybeHandle<Object> MakeAsyncTaskEvent(
       Handle<JSObject> task_event);
 
   // Mirror cache handling.
   void ClearMirrorCache();
 
-  // Returns a promise if the pushed try-catch handler matches the current one.
-  bool PromiseHasRejectHandler(Handle<JSObject> promise);
+  MaybeHandle<Object> PromiseHasUserDefinedRejectHandler(
+      Handle<JSObject> promise);
 
   void CallEventCallback(v8::DebugEvent event,
                          Handle<Object> exec_state,
                          Handle<Object> event_data,
                          v8::Debug::ClientData* client_data);
   void ProcessDebugEvent(v8::DebugEvent event,
                          Handle<JSObject> event_data,
                          bool auto_continue);
   void NotifyMessageHandler(v8::DebugEvent event,
                             Handle<JSObject> exec_state,
@@ skipping 194 matching lines @@
   // several frames above.
   // There is no calling conventions here, because it never actually gets
   // called, it only gets returned to.
   static void GenerateFrameDropperLiveEdit(MacroAssembler* masm);
 };
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_DEBUG_H_