[inspector] don't enter to debugger context for PromiseEventOccurred

Inspector doesn't use debugger context and this entering only slow down our async instrumentation.

BUG=v8:6189
R=yangguo@chromium.org

Review-Url: https://codereview.chromium.org/2816373004
Cr-Commit-Position: refs/heads/master@{#44665}

src/debug/debug-interface.h

@@ -169,8 +169,7 @@ MaybeLocal<UnboundScript> CompileInspectorScript(Isolate* isolate,
 class DebugDelegate {
  public:
   virtual ~DebugDelegate() {}
-  virtual void PromiseEventOccurred(v8::Local<v8::Context> context,
-                                    debug::PromiseDebugActionType type, int id,
+  virtual void PromiseEventOccurred(debug::PromiseDebugActionType type, int id,
                                     int parent_id, bool created_by_user) {}
   virtual void ScriptCompiled(v8::Local<Script> script,
                               bool has_compile_error) {}

src/debug/debug.cc

@@ -2044,9 +2044,6 @@ void Debug::OnAsyncTaskEvent(debug::PromiseDebugActionType type, int id,
   if (in_debug_scope() || ignore_events()) return;
   if (!debug_delegate_) return;
   SuppressDebug while_processing(this);
-  DebugScope debug_scope(isolate_->debug());
-  if (debug_scope.failed()) return;
-  HandleScope scope(isolate_);
   PostponeInterruptsScope no_interrupts(isolate_);
   DisableBreak no_recursive_break(this);
   bool created_by_user = false;
@@ -2058,9 +2055,7 @@ void Debug::OnAsyncTaskEvent(debug::PromiseDebugActionType type, int id,
         !it.done() &&
         !IsFrameBlackboxed(it.frame());
   }
-  debug_delegate_->PromiseEventOccurred(
-      Utils::ToLocal(debug_scope.GetContext()), type, id, parent_id,
-      created_by_user);
+  debug_delegate_->PromiseEventOccurred(type, id, parent_id, created_by_user);
 }
 
 void Debug::ProcessCompileEvent(v8::DebugEvent event, Handle<Script> script) {
@@ -2346,8 +2341,11 @@ bool Debug::PerformSideEffectCheckForCallback(Address function) {
 }
 
 void LegacyDebugDelegate::PromiseEventOccurred(
-    v8::Local<v8::Context> context, v8::debug::PromiseDebugActionType type,
-    int id, int parent_id, bool created_by_user) {
+    v8::debug::PromiseDebugActionType type, int id, int parent_id,
+    bool created_by_user) {
+  DebugScope debug_scope(isolate_->debug());
+  if (debug_scope.failed()) return;
+  HandleScope scope(isolate_);
   Handle<Object> event_data;
   if (isolate_->debug()->MakeAsyncTaskEvent(type, id).ToHandle(&event_data)) {
     ProcessDebugEvent(v8::AsyncTaskEvent, Handle<JSObject>::cast(event_data));

src/debug/debug.h

@@ -616,8 +616,7 @@ class Debug {
 class LegacyDebugDelegate : public v8::debug::DebugDelegate {
  public:
   explicit LegacyDebugDelegate(Isolate* isolate) : isolate_(isolate) {}
-  void PromiseEventOccurred(v8::Local<v8::Context> context,
-                            v8::debug::PromiseDebugActionType type, int id,
+  void PromiseEventOccurred(v8::debug::PromiseDebugActionType type, int id,
                             int parent_id, bool created_by_user) override;
   void ScriptCompiled(v8::Local<v8::debug::Script> script,
                       bool has_compile_error) override;

src/inspector/v8-debugger.cc

@@ -640,8 +640,7 @@ bool V8Debugger::IsFunctionBlackboxed(v8::Local<v8::debug::Script> script,
                                      end);
 }
 
-void V8Debugger::PromiseEventOccurred(v8::Local<v8::Context> context,
-                                      v8::debug::PromiseDebugActionType type,
+void V8Debugger::PromiseEventOccurred(v8::debug::PromiseDebugActionType type,
                                       int id, int parentId,
                                       bool createdByUser) {
   // Async task events from Promises are given misaligned pointers to prevent
@@ -652,10 +651,7 @@ void V8Debugger::PromiseEventOccurred(v8::Local<v8::Context> context,
   switch (type) {
     case v8::debug::kDebugPromiseCreated:
       asyncTaskCreatedForStack(task, parentTask);
-      if (createdByUser && parentTask) {
-        v8::Context::Scope contextScope(context);
-        asyncTaskCandidateForStepping(task);
-      }
+      if (createdByUser && parentTask) asyncTaskCandidateForStepping(task);
       break;
     case v8::debug::kDebugEnqueueAsyncFunction:
       asyncTaskScheduledForStack("async function", task, true);

src/inspector/v8-debugger.h

@@ -147,8 +147,7 @@ class V8Debugger : public v8::debug::DebugDelegate {
   void registerAsyncTaskIfNeeded(void* task);
 
   // v8::debug::DebugEventListener implementation.
-  void PromiseEventOccurred(v8::Local<v8::Context> context,
-                            v8::debug::PromiseDebugActionType type, int id,
+  void PromiseEventOccurred(v8::debug::PromiseDebugActionType type, int id,
                             int parentId, bool createdByUser) override;
   void ScriptCompiled(v8::Local<v8::debug::Script> script,
                       bool has_compile_error) override;