Copy the thread name to the stack for debugging purposes.

base/threading/thread.cc

Index: base/threading/thread.cc
diff --git a/base/threading/thread.cc b/base/threading/thread.cc
index aca4ddbaa02a11c37ef02b39b5e4c3da829f404e..ba3efc09b37ffeea63df04f3e24829c7aed6a43e 100644
--- a/base/threading/thread.cc
+++ b/base/threading/thread.cc
@@ -5,6 +5,7 @@
 #include "base/threading/thread.h"
 
 #include "base/bind.h"
+#include "base/debug/alias.h"
 #include "base/lazy_instance.h"
 #include "base/third_party/dynamic_annotations/dynamic_annotations.h"
 #include "base/threading/thread_id_name_manager.h"
@@ -172,6 +173,19 @@ bool Thread::GetThreadWasQuitProperly() {
 
 void Thread::ThreadMain() {
   {
+#if defined(OS_MACOSX)
+    // Store the thread name on the stack to debug <http://crbug.com/274705>.
+    // End with a byte sequence of <EOT><BEL><NUL> to make it easier to grep in
+    // the minidump stack dump.
+    const size_t kThreadNameSize = 50;
+    char thread_name[kThreadNameSize] = { 0 };

[Mark Mentovai, 2013/09/12 18:52:18]

Oh, you’re using strncpy, OK, you can get rid of this. I was thinking snprintf,
which is what I usually use when I’m unsure about overflow, since it portably
guarantees NUL-termination.

+    strncpy(thread_name, name_.c_str(), kThreadNameSize);
+    thread_name[kThreadNameSize - 1] = '\0';
+    thread_name[kThreadNameSize - 2] = '\7';
+    thread_name[kThreadNameSize - 3] = '\3';
+    base::debug::Alias(thread_name);
+#endif
+
     // The message loop for this thread.
     // Allocated on the heap to centralize any leak reports at this line.
     scoped_ptr<MessageLoop> message_loop(
@@ -217,6 +231,10 @@ void Thread::ThreadMain() {
 
     // We can't receive messages anymore.
     message_loop_ = NULL;
+
+#if defined(OS_MACOSX)
+    base::debug::Alias(thread_name);
+#endif
   }
 }