Record OSThread::trace_id() instead of OSThread::id() in profile samples.

runtime/vm/profiler.cc

Index: runtime/vm/profiler.cc
diff --git a/runtime/vm/profiler.cc b/runtime/vm/profiler.cc
index f7484f521a3c1b57bd5e2e84a1b45babf06b17f4..9f820b0757357efc42093df13a70b50ce225ac15 100644
--- a/runtime/vm/profiler.cc
+++ b/runtime/vm/profiler.cc
@@ -898,7 +898,7 @@ void Profiler::SampleAllocation(Thread* thread, intptr_t cid) {
       return;
     }
 
-    Sample* sample = SetupSample(thread, sample_buffer, os_thread->id());
+    Sample* sample = SetupSample(thread, sample_buffer, os_thread->trace_id());
     sample->SetAllocationCid(cid);
     ProfilerNativeStackWalker native_stack_walker(isolate,
                                                   sample,
@@ -910,7 +910,7 @@ void Profiler::SampleAllocation(Thread* thread, intptr_t cid) {
                                                   sp);
     native_stack_walker.walk();
   } else if (exited_dart_code) {
-    Sample* sample = SetupSample(thread, sample_buffer, os_thread->id());
+    Sample* sample = SetupSample(thread, sample_buffer, os_thread->trace_id());
     sample->SetAllocationCid(cid);
     ProfilerDartExitStackWalker dart_exit_stack_walker(thread,
                                                        isolate,
@@ -920,7 +920,7 @@ void Profiler::SampleAllocation(Thread* thread, intptr_t cid) {
   } else {
     // Fall back.
     uintptr_t pc = GetProgramCounter();
-    Sample* sample = SetupSample(thread, sample_buffer, os_thread->id());
+    Sample* sample = SetupSample(thread, sample_buffer, os_thread->trace_id());
     sample->SetAllocationCid(cid);
     sample->SetAt(0, pc);
   }
@@ -1000,7 +1000,7 @@ void Profiler::SampleThread(Thread* thread,
   }
 
   // Setup sample.
-  Sample* sample = SetupSample(thread, sample_buffer, os_thread->id());
+  Sample* sample = SetupSample(thread, sample_buffer, os_thread->trace_id());
   // Increment counter for vm tag.
   VMTagCounters* counters = isolate->vm_tag_counters();
   ASSERT(counters != NULL);