Change TraceDataEndPoint::ReceiveTraceChunk() to accept unique_ptr<string>

content/browser/tracing/tracing_controller_impl.h

Index: content/browser/tracing/tracing_controller_impl.h
diff --git a/content/browser/tracing/tracing_controller_impl.h b/content/browser/tracing/tracing_controller_impl.h
index 7d769e97794361b943f0f9ab099dc473df647f07..818f1d5f1fcf681e294c4edca249056f448ee295 100644
--- a/content/browser/tracing/tracing_controller_impl.h
+++ b/content/browser/tracing/tracing_controller_impl.h
@@ -37,7 +37,7 @@ class TracingUI;
 class CONTENT_EXPORT TraceDataEndpoint
     : public base::RefCountedThreadSafe<TraceDataEndpoint> {
  public:
-  virtual void ReceiveTraceChunk(const std::string& chunk) {}
+  virtual void ReceiveTraceChunk(std::unique_ptr<std::string> chunk) {}
   virtual void ReceiveTraceFinalContents(
       std::unique_ptr<const base::DictionaryValue> metadata) {}