Remove Isolate::cpu_profiler() usage in api.cc

src/api.cc

Index: src/api.cc
diff --git a/src/api.cc b/src/api.cc
index 5bd6fa6c37378a01fa8b682838d415791e072c40..5b2e4a03d298d4e64b9c366b3c1d5e7024f3d359 100644
--- a/src/api.cc
+++ b/src/api.cc
@@ -8230,9 +8230,8 @@ const std::vector<CpuProfileDeoptInfo>& CpuProfileNode::GetDeoptInfos() const {
 
 void CpuProfile::Delete() {
   i::CpuProfile* profile = reinterpret_cast<i::CpuProfile*>(this);
-  i::Isolate* isolate = profile->top_down()->isolate();
-  i::CpuProfiler* profiler = isolate->cpu_profiler();
-  DCHECK(profiler != NULL);
+  i::CpuProfiler* profiler = profile->cpu_profiler();
+  DCHECK(profiler != nullptr);
   profiler->DeleteProfile(profile);
 }