Revert 114494 - Remove BindStateHolder and have Bind() return a Callback<> object directly.

base/debug/trace_event_unittest.cc

Index: base/debug/trace_event_unittest.cc
===================================================================
--- base/debug/trace_event_unittest.cc	(revision 114494)
+++ base/debug/trace_event_unittest.cc	(working copy)
@@ -42,7 +42,7 @@
   // up multiple times when testing AtExit. Use ManualTestSetUp for this.
   void ManualTestSetUp();
   void OnTraceDataCollected(
-      const scoped_refptr<TraceLog::RefCountedString>& events_str);
+      scoped_refptr<TraceLog::RefCountedString> events_str);
   DictionaryValue* FindMatchingTraceEntry(const JsonKeyValue* key_values);
   DictionaryValue* FindNamePhase(const char* name, const char* phase);
   DictionaryValue* FindNamePhaseKeyValue(const char* name,
@@ -89,7 +89,7 @@
 }
 
 void TraceEventTestFixture::OnTraceDataCollected(
-    const scoped_refptr<TraceLog::RefCountedString>& events_str) {
+    scoped_refptr<TraceLog::RefCountedString> events_str) {
   AutoLock lock(lock_);
   json_output_.json_output.clear();
   trace_buffer_.Start();