Clean up verbose logging.

Change-Id: I6b01980e7145c4f8d25a5b50f620903f61a1b427
diff --git a/src/thread_list.h b/src/thread_list.h
index d93ec3b..5da9877 100644
--- a/src/thread_list.h
+++ b/src/thread_list.h
@@ -28,7 +28,7 @@
   static const uint32_t kInvalidId = 0;
   static const uint32_t kMainId = 1;
 
-  explicit ThreadList(bool verbose);
+  explicit ThreadList();
   ~ThreadList();
 
   void Dump(std::ostream& os);
@@ -68,8 +68,6 @@
 
   static void ModifySuspendCount(Thread* thread, int delta, bool for_debugger);
 
-  bool verbose_;
-
   mutable Mutex thread_list_lock_;
   std::bitset<kMaxThreadId> allocated_ids_;
   std::list<Thread*> list_;