Rename webrtc/base -> webrtc/rtc_base

NOPRESUBMIT=True # cpplint errors that aren't caused by this CL.
NOTRY=True
NOTREECHECKS=True
TBR=kwiberg@webrtc.org, kjellander@webrtc.org

Bug: webrtc:7634
Change-Id: I3cca0fbaa807b563c95979cccd6d1bec32055f36
Reviewed-on: https://chromium-review.googlesource.com/562156
Commit-Queue: Edward Lemur <ehmaldonado@webrtc.org>
Reviewed-by: Mirko Bonadei <mbonadei@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#18919}
diff --git a/webrtc/examples/peerconnection/server/utils.cc b/webrtc/examples/peerconnection/server/utils.cc
index 93a6d05..85f5f9e 100644
--- a/webrtc/examples/peerconnection/server/utils.cc
+++ b/webrtc/examples/peerconnection/server/utils.cc
@@ -12,7 +12,7 @@
 
 #include <stdio.h>
 
-#include "webrtc/base/stringencode.h"
+#include "webrtc/rtc_base/stringencode.h"
 
 using rtc::ToString;