[profiler] Fix a memory leak of CodeEvent objects

src/profiler/profile-generator.h

Index: src/profiler/profile-generator.h
diff --git a/src/profiler/profile-generator.h b/src/profiler/profile-generator.h
index 1b3cad6dc3ee7a2aa804103884d369ee769c9143..c108fbd61b834c93c939c85bec4a563d1b574d3c 100644
--- a/src/profiler/profile-generator.h
+++ b/src/profiler/profile-generator.h
@@ -368,7 +368,7 @@ class CpuProfilesCollection {
 
 class ProfileGenerator {
  public:
-  ProfileGenerator(Isolate* isolate, CpuProfilesCollection* profiles);
+  explicit ProfileGenerator(CpuProfilesCollection* profiles);
 
   void RecordTickSample(const TickSample& sample);
 
@@ -378,7 +378,6 @@ class ProfileGenerator {
   CodeEntry* FindEntry(void* address);
   CodeEntry* EntryForVMState(StateTag tag);
 
-  Isolate* isolate_;
   CpuProfilesCollection* profiles_;
   CodeMap code_map_;