Deletes base::MessageLoop::set_thread_name().

base/message_loop/message_loop.cc

Index: base/message_loop/message_loop.cc
diff --git a/base/message_loop/message_loop.cc b/base/message_loop/message_loop.cc
index 3fef91be460dc26bd81028d8e8a5d20477833091..abac00f156595a37cf2d76f8ecdf952c3f9ab17d 100644
--- a/base/message_loop/message_loop.cc
+++ b/base/message_loop/message_loop.cc
@@ -18,6 +18,7 @@
 #include "base/metrics/statistics_recorder.h"
 #include "base/run_loop.h"
 #include "base/third_party/dynamic_annotations/dynamic_annotations.h"
+#include "base/threading/thread_id_name_manager.h"
 #include "base/threading/thread_local.h"
 #include "base/threading/thread_task_runner_handle.h"
 #include "base/time/time.h"
@@ -398,7 +399,8 @@ MessageLoop::MessageLoop(Type type, MessagePumpFactoryCallback pump_factory)
       incoming_task_queue_(new internal::IncomingTaskQueue(this)),
       unbound_task_runner_(
           new internal::MessageLoopTaskRunner(incoming_task_queue_)),
-      task_runner_(unbound_task_runner_) {
+      task_runner_(unbound_task_runner_),
+      thread_id_(kInvalidThreadId) {
   // If type is TYPE_CUSTOM non-null pump_factory must be given.
   DCHECK(type_ != TYPE_CUSTOM || !pump_factory_.is_null());
 }
@@ -416,9 +418,14 @@ void MessageLoop::BindToCurrentThread() {
   incoming_task_queue_->StartScheduling();
   unbound_task_runner_->BindToCurrentThread();
   unbound_task_runner_ = nullptr;
+  thread_id_ = PlatformThread::CurrentId();

[gab, 2016/05/20 20:25:39]

This needs to be synchronized as it's set outside the constructor. Though all
that's required is a memory barrier, @danakj think this warrants a Lock? In
practice we probably have an implicit memory barrier from the task posting
machinery... or we could add an explicit memory barrier instead of a lock?

Or we just call the method GetThreadNameForLogging() and document it as being
synchronized and only intended to be used for logging?

[alokp, 2016/06/01 19:23:18]

Done. Can you please check the barrier usage and memory_order. Thanks!

   SetThreadTaskRunnerHandle();
 }
 
+std::string MessageLoop::GetThreadName() const {
+  return ThreadIdNameManager::GetInstance()->GetName(thread_id_);
+}
+
 void MessageLoop::SetTaskRunner(
     scoped_refptr<SingleThreadTaskRunner> task_runner) {
   DCHECK_EQ(this, current());
@@ -557,9 +564,10 @@ void MessageLoop::StartHistogrammer() {
 #if !defined(OS_NACL)  // NaCl build has no metrics code.
   if (enable_histogrammer_ && !message_histogram_
       && StatisticsRecorder::IsActive()) {
-    DCHECK(!thread_name_.empty());
+    std::string thread_name = GetThreadName();
+    DCHECK(!thread_name.empty());
     message_histogram_ = LinearHistogram::FactoryGetWithRangeDescription(
-        "MsgLoop:" + thread_name_,
+        "MsgLoop:" + thread_name,
         kLeastNonZeroMessageId, kMaxMessageId,
         kNumberOfDistinctMessagesDisplayed,
         HistogramBase::kHexRangePrintingFlag,