Pass StringPiece by value

Reviewed By: yfeldblum

Differential Revision: D16785914

fbshipit-source-id: 73ade28f7aa300ce5e278e2ff2f56f4aafef9533

folly/io/async/ScopedEventBaseThread.cpp

@@ -49,7 +49,7 @@ static void run(
 ScopedEventBaseThread::ScopedEventBaseThread()
     : ScopedEventBaseThread(nullptr, "") {}
 
-ScopedEventBaseThread::ScopedEventBaseThread(const StringPiece& name)
+ScopedEventBaseThread::ScopedEventBaseThread(StringPiece name)
     : ScopedEventBaseThread(nullptr, name) {}
 
 ScopedEventBaseThread::ScopedEventBaseThread(EventBaseManager* ebm)
@@ -57,7 +57,7 @@ ScopedEventBaseThread::ScopedEventBaseThread(EventBaseManager* ebm)
 
 ScopedEventBaseThread::ScopedEventBaseThread(
     EventBaseManager* ebm,
-    const StringPiece& name)
+    StringPiece name)
     : ebm_(ebm ? ebm : EventBaseManager::get()) {
   new (&eb_) EventBase();
   th_ = thread(run, ebm_, &eb_, &stop_, name);

folly/io/async/ScopedEventBaseThread.h

@@ -39,11 +39,9 @@ typedef Range<const char*> StringPiece;
 class ScopedEventBaseThread : public IOExecutor, public SequencedExecutor {
  public:
   ScopedEventBaseThread();
-  explicit ScopedEventBaseThread(const StringPiece& name);
+  explicit ScopedEventBaseThread(StringPiece name);
   explicit ScopedEventBaseThread(EventBaseManager* ebm);
-  explicit ScopedEventBaseThread(
-      EventBaseManager* ebm,
-      const StringPiece& name);
+  explicit ScopedEventBaseThread(EventBaseManager* ebm, StringPiece name);
   ~ScopedEventBaseThread();
 
   EventBase* getEventBase() const {