Attempt at enabling profiler

runtime/vm/profiler_macos.cc

 // Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "platform/globals.h"
 #if defined(TARGET_OS_MACOS)
 
 #include "vm/isolate.h"
 #include "vm/json_stream.h"
 #include "vm/profiler.h"
@@ skipping 11 matching lines @@
                           uintptr_t stack_upper) {
   SampleBuffer* sample_buffer = profiler_data->sample_buffer();
   Sample* sample = sample_buffer->ReserveSample();
   ASSERT(sample != NULL);
   sample->timestamp = OS::GetCurrentTimeMicros();
   // TODO(johnmccutchan): Make real use of vm_tags and runtime_tags.
   // Issue # 14777
   sample->vm_tags = Sample::kExecuting;
   sample->runtime_tags = 0;
   int64_t cpu_usage = 0;
-  // TODO(johnmccutchan): Thread::GetThreadCpuUsage on MacOS.
+  Thread::GetThreadCpuUsage(profiler_data->thread_id(), &cpu_usage);
   sample->cpu_usage = profiler_data->ComputeDeltaAndSetCpuUsage(cpu_usage);
   ProfilerSampleStackWalker stackWalker(sample, stack_lower, stack_upper,
                                         pc, fp, sp);
   stackWalker.walk();
 }
 
 
 static void ProfileSignalAction(int signal, siginfo_t* info, void* context_) {
   if (signal != SIGPROF) {
     return;
@@ skipping 81 matching lines @@
     int64_t current_time = OS::GetCurrentTimeMicros();
     int64_t next_sample = SampleAndRescheduleIsolates(current_time);
     lock.WaitMicros(next_sample);
   }
 }
 
 
 }  // namespace dart
 
 #endif  // defined(TARGET_OS_MACOS)