Allow CpuProfiler::SetIdle to be called while executing JS.

src/api.cc

Index: src/api.cc
diff --git a/src/api.cc b/src/api.cc
index 47fc1ce1b2f62ba22dd739aeba225c14da1b9230..3b1f72ebf31734d63447c54f9d9700dc8ff906bc 100644
--- a/src/api.cc
+++ b/src/api.cc
@@ -8354,7 +8354,7 @@ CpuProfile* CpuProfiler::StopProfiling(Local<String> title) {
 void CpuProfiler::SetIdle(bool is_idle) {
   i::Isolate* isolate = reinterpret_cast<i::CpuProfiler*>(this)->isolate();
   v8::StateTag state = isolate->current_vm_state();
-  DCHECK(state == v8::EXTERNAL || state == v8::IDLE);
+  DCHECK(state == v8::JS || state == v8::EXTERNAL || state == v8::IDLE);
   if (isolate->js_entry_sp() != NULL) return;
   if (is_idle) {
     isolate->set_current_vm_state(v8::IDLE);