[profiler] Fix a memory leak of CodeEvent objects

src/profiler/profile-generator.h

 // Copyright 2011 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef V8_PROFILER_PROFILE_GENERATOR_H_
 #define V8_PROFILER_PROFILE_GENERATOR_H_
 
 #include <map>
 #include "src/allocation.h"
 #include "src/base/hashmap.h"
@@ skipping 350 matching lines @@
   // Accessed by VM thread and profile generator thread.
   List<CpuProfile*> current_profiles_;
   base::Semaphore current_profiles_semaphore_;
 
   DISALLOW_COPY_AND_ASSIGN(CpuProfilesCollection);
 };
 
 
 class ProfileGenerator {
  public:
-  ProfileGenerator(Isolate* isolate, CpuProfilesCollection* profiles);
+  explicit ProfileGenerator(CpuProfilesCollection* profiles);
 
   void RecordTickSample(const TickSample& sample);
 
   CodeMap* code_map() { return &code_map_; }
 
  private:
   CodeEntry* FindEntry(void* address);
   CodeEntry* EntryForVMState(StateTag tag);
 
-  Isolate* isolate_;
   CpuProfilesCollection* profiles_;
   CodeMap code_map_;
 
   DISALLOW_COPY_AND_ASSIGN(ProfileGenerator);
 };
 
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_PROFILER_PROFILE_GENERATOR_H_