Add slides for Gerrit 2.15 talk

Change-Id: I10e029705261feb4dea7c6764852549570b883e8
diff --git a/sessions/new-in-2.15.md b/sessions/new-in-2.15.md
index d2f9c21..d00da62 100644
--- a/sessions/new-in-2.15.md
+++ b/sessions/new-in-2.15.md
@@ -2,4 +2,6 @@
 
 Preview of the new features coming in the next release of Gerrit.
 
+[Slides](https://storage.googleapis.com/gerrit-talks/summit/2017/Whats-New-in-Gerrit-2.15.pdf)
+
 *[Dave Borowitz, Google](../speakers.md#dborowitz)*