[inspector] async stacks for Promise.then calls...

src/debug/debug.h

Index: src/debug/debug.h
diff --git a/src/debug/debug.h b/src/debug/debug.h
index 9a5060088fdfd94d8ab97b08d87f5b107e5e7b87..089c8d3e01fa7cce3eb13f2086eaa51f04912063 100644
--- a/src/debug/debug.h
+++ b/src/debug/debug.h
@@ -12,6 +12,7 @@
 #include "src/base/hashmap.h"
 #include "src/base/platform/platform.h"
 #include "src/debug/debug-interface.h"
+#include "src/debug/interface-types.h"
 #include "src/execution.h"
 #include "src/factory.h"
 #include "src/flags.h"
@@ -407,7 +408,7 @@ class Debug {
   void OnPromiseReject(Handle<Object> promise, Handle<Object> value);
   void OnCompileError(Handle<Script> script);
   void OnAfterCompile(Handle<Script> script);
-  void OnAsyncTaskEvent(Handle<String> type, Handle<Object> id,
+  void OnAsyncTaskEvent(debug::AsyncTaskEventType, Handle<Object> id,
                         Handle<String> name);
 
   // API facing.
@@ -455,6 +456,8 @@ class Debug {
 
   void RecordGenerator(Handle<JSGeneratorObject> generator_object);
 
+  Handle<Object> NextAsyncTaskId(Handle<JSObject> promise);
+
   // Returns whether the operation succeeded. Compilation can only be triggered
   // if a valid closure is passed as the second argument, otherwise the shared
   // function needs to be compiled already.
@@ -584,7 +587,7 @@ class Debug {
       Handle<Object> promise);
   MUST_USE_RESULT MaybeHandle<Object> MakeCompileEvent(
       Handle<Script> script, v8::DebugEvent type);
-  MUST_USE_RESULT MaybeHandle<Object> MakeAsyncTaskEvent(Handle<String> type,
+  MUST_USE_RESULT MaybeHandle<Object> MakeAsyncTaskEvent(Handle<Smi> type,
                                                          Handle<Object> id,
                                                          Handle<String> name);
 
@@ -702,6 +705,9 @@ class Debug {
     Handle<Object> return_value_;
 
     Object* suspended_generator_;
+
+    int async_task_count_;
+    Handle<JSWeakMap> async_task_ids_;
   };
 
   // Storage location for registers when handling debug break calls