Fix DevTools CPU profiler after isolates merge.

src/cpu-profiler.cc

 // 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 423 matching lines @@
       Logger::CALLBACK_TAG, "set ", name, entry_point);
 }
 
 
 CpuProfiler::CpuProfiler()
     : profiles_(new CpuProfilesCollection()),
       next_profile_uid_(1),
       token_enumerator_(new TokenEnumerator()),
       generator_(NULL),
       processor_(NULL),
+      need_to_stop_sampler_(false),
       is_profiling_(false) {
 }
 
 
 CpuProfiler::~CpuProfiler() {
   delete token_enumerator_;
   delete profiles_;
 }
 
 
@@ skipping 25 matching lines @@
         bool saved_log_code_flag = FLAG_log_code;
         FLAG_log_code = true;
         LOGGER->LogCodeObjects();
         FLAG_log_code = saved_log_code_flag;
       }
       LOGGER->LogCompiledFunctions();
       LOGGER->LogAccessorCallbacks();
     }
     // Enable stack sampling.
     Sampler* sampler = reinterpret_cast<Sampler*>(LOGGER->ticker_);
-    if (!sampler->IsActive()) sampler->Start();
+    if (!sampler->IsActive()) {
+      sampler->Start();
+      need_to_stop_sampler_ = true;
+    }
     sampler->IncreaseProfilingDepth();
   }
 }
 
 
 CpuProfile* CpuProfiler::StopCollectingProfile(const char* title) {
   const double actual_sampling_rate = generator_->actual_sampling_rate();
   StopProcessorIfLastProfile(title);
   CpuProfile* result =
       profiles_->StopProfiling(TokenEnumerator::kNoSecurityToken,
@@ skipping 13 matching lines @@
   StopProcessorIfLastProfile(profile_title);
   int token = token_enumerator_->GetTokenId(security_token);
   return profiles_->StopProfiling(token, profile_title, actual_sampling_rate);
 }
 
 
 void CpuProfiler::StopProcessorIfLastProfile(const char* title) {
   if (profiles_->IsLastProfile(title)) {
     Sampler* sampler = reinterpret_cast<Sampler*>(LOGGER->ticker_);
     sampler->DecreaseProfilingDepth();
-    sampler->Stop();
+    if (need_to_stop_sampler_) {
+      sampler->Stop();
+      need_to_stop_sampler_ = false;
+    }
     processor_->Stop();
     processor_->Join();
     delete processor_;
     delete generator_;
     processor_ = NULL;
     NoBarrier_Store(&is_profiling_, false);
     generator_ = NULL;
     LOGGER->logging_nesting_ = saved_logging_nesting_;
   }
 }
@@ skipping 19 matching lines @@
 #ifdef ENABLE_LOGGING_AND_PROFILING
   Isolate* isolate = Isolate::Current();
   if (isolate->cpu_profiler() != NULL) {
     delete isolate->cpu_profiler();
   }
   isolate->set_cpu_profiler(NULL);
 #endif
 }
 
 } }  // namespace v8::internal