A64: Synchronize with r15204.

src/sampler.cc

 // Copyright 2013 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 493 matching lines @@
       OS::Sleep(interval_);
     }
   }
 
  private:
 #if defined(USE_SIGNALS)
 
   void SampleContext(Sampler* sampler) {
     if (!SignalHandler::Installed()) return;
     pthread_t tid = sampler->platform_data()->vm_tid();
-    int result = pthread_kill(tid, SIGPROF);
-    USE(result);
-    ASSERT(result == 0);
+    pthread_kill(tid, SIGPROF);
   }
 
 #elif defined(__MACH__)
 
   void SampleContext(Sampler* sampler) {
     thread_act_t profiled_thread = sampler->platform_data()->profiled_thread();
     Isolate* isolate = sampler->isolate();
 
     SampleHelper helper;
     TickSample* sample = helper.Init(sampler, isolate);
@@ skipping 173 matching lines @@
   SamplerThread::RemoveActiveSampler(this);
   SetActive(false);
 }
 
 void Sampler::SampleStack(TickSample* sample) {
   sample->Trace(isolate_);
   if (++samples_taken_ < 0) samples_taken_ = 0;
 }
 
 } }  // namespace v8::internal