Roll AppRTC 3168981..e7f6cae

Change log: https://chromium.googlesource.com/external/webrtc/apprtc/+log/3168981..e7f6cae

Mainly to bring in the fix for websocket dependency
that seems to cause flakiness on the bots:
https://chromium.googlesource.com/external/webrtc/apprtc/+/e7f6cae744590cc2191e50fe673a0cca5d55b226

BUG=567598
TBR=phoglund@chromium.org

Review URL: https://codereview.chromium.org/1509873002 .
diff --git a/DEPS b/DEPS
index c53c21e..ca2e3cd 100644
--- a/DEPS
+++ b/DEPS
@@ -8,7 +8,7 @@
 
 deps = {
   'apprtc':
-    Var('git_url') + '/external/webrtc/apprtc@3168981efed7629fabee731a5ee74d3716b50652',
+    Var('git_url') + '/external/webrtc/apprtc@e7f6cae744590cc2191e50fe673a0cca5d55b226',
   'webrtc.DEPS/third_party/manifestdestiny':
     Var('git_url') + '/chromium/deps/manifestdestiny.git@46ae53ac463e23bfefec374a81806355ea598ac4',
   'webrtc.DEPS/third_party/mozdownload':