Reimplement profiler sampler on Mac OS X to get it working under Chromium.

src/platform-freebsd.cc

 // Copyright 2006-2008 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 543 matching lines @@
     mcontext_t& mcontext = ucontext->uc_mcontext;
 #if defined (__arm__) || defined(__thumb__)
     sample.pc = mcontext.mc_r15;
     sample.sp = mcontext.mc_r13;
     sample.fp = mcontext.mc_r11;
 #else
     sample.pc = mcontext.mc_eip;
     sample.sp = mcontext.mc_esp;
     sample.fp = mcontext.mc_ebp;
 #endif
+    active_sampler_->SampleStack(&sample);
   }
 
   // We always sample the VM state.
   sample.state = Logger::state();
 
   active_sampler_->Tick(&sample);
 }
 
 
 class Sampler::PlatformData : public Malloced {
@@ skipping 55 matching lines @@
   }
 
   // This sampler is no longer the active sampler.
   active_sampler_ = NULL;
   active_ = false;
 }
 
 #endif  // ENABLE_LOGGING_AND_PROFILING
 
 } }  // namespace v8::internal