From fe634e7c1216729ee2a09299bc465a800301d508 Mon Sep 17 00:00:00 2001
From: Paul Irish <paul.irish@gmail.com>
Date: Fri, 29 Jul 2016 16:57:42 -0400
Subject: [PATCH] trace reading: only bind to the first tracingComplete event.

---
 lighthouse-core/gather/drivers/driver.js | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lighthouse-core/gather/drivers/driver.js b/lighthouse-core/gather/drivers/driver.js
index 1ef21d7fd3c8..8505081f28c1 100644
--- a/lighthouse-core/gather/drivers/driver.js
+++ b/lighthouse-core/gather/drivers/driver.js
@@ -255,7 +255,7 @@ class Driver {
   endTrace() {
     return new Promise((resolve, reject) => {
       // When the tracing has ended this will fire with a stream handle.
-      this.on('Tracing.tracingComplete', streamHandle => {
+      this.once('Tracing.tracingComplete', streamHandle => {
         this._readTraceFromStream(streamHandle)
             .then(traceContents => resolve(traceContents));
       });