Add |joinable| to Thread::Options

base/threading/thread.cc

Index: base/threading/thread.cc
diff --git a/base/threading/thread.cc b/base/threading/thread.cc
index 98610a63c09875878ffceca6417d7af16980ca89..df8f661bc19e50f7d71a3c8fdc0e54351f1f3260 100644
--- a/base/threading/thread.cc
+++ b/base/threading/thread.cc
@@ -28,7 +28,7 @@ namespace {
 // because its Stop method was called.  This allows us to catch cases where
 // MessageLoop::QuitWhenIdle() is called directly, which is unexpected when
 // using a Thread to setup and run a MessageLoop.
-base::LazyInstance<base::ThreadLocalBoolean> lazy_tls_bool =
+base::LazyInstance<base::ThreadLocalBoolean>::Leaky lazy_tls_bool =
     LAZY_INSTANCE_INITIALIZER;
 
 }  // namespace
@@ -74,6 +74,8 @@ bool Thread::StartWithOptions(const Options& options) {
   DCHECK(owning_sequence_checker_.CalledOnValidSequencedThread());
   DCHECK(!message_loop_);
   DCHECK(!IsRunning());
+  DCHECK(!stopping_) << "Starting a non-joinable thread a second time? That's "
+                     << "not allowed!";
 #if defined(OS_WIN)
   DCHECK((com_status_ != STA) ||
       (options.message_loop_type == MessageLoop::TYPE_UI));
@@ -100,8 +102,13 @@ bool Thread::StartWithOptions(const Options& options) {
   // fixed).
   {
     AutoLock lock(thread_lock_);
-    if (!PlatformThread::CreateWithPriority(options.stack_size, this, &thread_,
-                                            options.priority)) {
+    bool success =
+        options.joinable
+            ? PlatformThread::CreateWithPriority(options.stack_size, this,
+                                                 &thread_, options.priority)
+            : PlatformThread::CreateNonJoinableWithPriority(
+                  options.stack_size, this, options.priority);
+    if (!success) {
       DLOG(ERROR) << "failed to create thread";
       message_loop_ = nullptr;
       return false;
@@ -141,11 +148,12 @@ void Thread::Stop() {
   // DCHECK(owning_sequence_checker_.CalledOnValidSequencedThread());
   AutoLock lock(thread_lock_);
 
+  StopSoon();

[gab, 2016/07/25 21:09:00]

Note: this is causing try job failures in unittests because
TestBrowserThreadBundle binds the same MessageLoop to multiple Thread objects.
Beautiful, will address tomorrow. Cheers!

+
+  // Can't join if the |thread_| is either already gone or is non-joinable.
   if (thread_.is_null())
     return;
 
-  StopSoon();
-
   // Wait for the thread to exit.
   //
   // TODO(darin): Unfortunately, we need to keep |message_loop_| around until