Support idle time in CPU profiler

src/api.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 7628 matching lines @@
       reinterpret_cast<i::CpuProfiler*>(this)->StopProfiling(
           *Utils::OpenHandle(*title)));
 }
 
 
 void CpuProfiler::DeleteAllCpuProfiles() {
   reinterpret_cast<i::CpuProfiler*>(this)->DeleteAllProfiles();
 }
 
 
+void CpuProfiler::SetIdle(bool is_idle) {
+  i::Isolate* isolate = reinterpret_cast<i::CpuProfiler*>(this)->isolate();
+  i::StateTag state = isolate->current_vm_state();
+  ASSERT(state == i::EXTERNAL || state == i::IDLE);
+  if (isolate->js_entry_sp() != NULL) return;
+  if (is_idle) {
+    isolate->set_current_vm_state(i::IDLE);
+  } else if (state == i::IDLE) {
+    isolate->set_current_vm_state(i::EXTERNAL);
+  }
+}
+
+
 static i::HeapGraphEdge* ToInternal(const HeapGraphEdge* edge) {
   return const_cast<i::HeapGraphEdge*>(
       reinterpret_cast<const i::HeapGraphEdge*>(edge));
 }
 
 
 HeapGraphEdge::Type HeapGraphEdge::GetType() const {
   i::Isolate* isolate = i::Isolate::Current();
   IsDeadCheck(isolate, "v8::HeapGraphEdge::GetType");
   return static_cast<HeapGraphEdge::Type>(ToInternal(this)->type());
@@ skipping 510 matching lines @@
   Isolate* isolate = reinterpret_cast<Isolate*>(info.GetIsolate());
   Address callback_address =
       reinterpret_cast<Address>(reinterpret_cast<intptr_t>(callback));
   VMState<EXTERNAL> state(isolate);
   ExternalCallbackScope call_scope(isolate, callback_address);
   return callback(info);
 }
 
 
 } }  // namespace v8::internal