Fix CPU profiler crash in start / stop sequence when non-existent name is passed

src/cpu-profiler.h

 // Copyright 2010 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 242 matching lines @@
   }
 
  private:
   CpuProfiler();
   ~CpuProfiler();
   void StartCollectingProfile(const char* title);
   void StartCollectingProfile(String* title);
   void StartProcessorIfNotStarted();
   CpuProfile* StopCollectingProfile(const char* title);
   CpuProfile* StopCollectingProfile(Object* security_token, String* title);
-  void StopProcessorIfLastProfile();
+  void StopProcessorIfLastProfile(const char* title);
 
   CpuProfilesCollection* profiles_;
   unsigned next_profile_uid_;
   TokenEnumerator* token_enumerator_;
   ProfileGenerator* generator_;
   ProfilerEventsProcessor* processor_;
   int saved_logging_nesting_;
 
   static CpuProfiler* singleton_;
 
 #else
   static INLINE(bool is_profiling()) { return false; }
 #endif  // ENABLE_LOGGING_AND_PROFILING
 
  private:
   DISALLOW_COPY_AND_ASSIGN(CpuProfiler);
 };
 
 } }  // namespace v8::internal
 
 
 #endif  // V8_CPU_PROFILER_H_