[inspector] introduced stepIntoAsync for chained callbacks

src/api.cc

 // 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.
 
 #include "src/api.h"
 
 #include <string.h>  // For memcpy, strlen.
 #ifdef V8_USE_ADDRESS_SANITIZER
 #include <sanitizer/asan_interface.h>
 #endif  // V8_USE_ADDRESS_SANITIZER
@@ skipping 9021 matching lines @@
 void debug::PrepareStep(Isolate* v8_isolate, StepAction action) {
   i::Isolate* isolate = reinterpret_cast<i::Isolate*>(v8_isolate);
   ENTER_V8(isolate);
   CHECK(isolate->debug()->CheckExecutionState());
   // Clear all current stepping setup.
   isolate->debug()->ClearStepping();
   // Prepare step.
   isolate->debug()->PrepareStep(static_cast<i::StepAction>(action));
 }
 
+void debug::ClearStepping(Isolate* v8_isolate) {
+  i::Isolate* isolate = reinterpret_cast<i::Isolate*>(v8_isolate);
+  ENTER_V8(isolate);
+  CHECK(isolate->debug()->CheckExecutionState());
+  // Clear all current stepping setup.
+  isolate->debug()->ClearStepping();
+}
+
 bool debug::HasNonBlackboxedFrameOnStack(Isolate* v8_isolate) {
   i::Isolate* isolate = reinterpret_cast<i::Isolate*>(v8_isolate);
   ENTER_V8(isolate);
   i::HandleScope scope(isolate);
   for (i::StackTraceFrameIterator it(isolate); !it.done(); it.Advance()) {
     if (!it.is_javascript()) continue;
     if (!isolate->debug()->IsFrameBlackboxed(it.javascript_frame())) {
       return true;
     }
   }
@@ skipping 994 matching lines @@
   Address callback_address =
       reinterpret_cast<Address>(reinterpret_cast<intptr_t>(callback));
   VMState<EXTERNAL> state(isolate);
   ExternalCallbackScope call_scope(isolate, callback_address);
   callback(info);
 }
 
 
 }  // namespace internal
 }  // namespace v8