Enable cpplint for webrtc/examples and fix all uncovered cpplint errors.

webrtc/examples/peerconnection/server/data_socket.h

Index: webrtc/examples/peerconnection/server/data_socket.h
diff --git a/webrtc/examples/peerconnection/server/data_socket.h b/webrtc/examples/peerconnection/server/data_socket.h
index 454ad3978ab33a3c9d65eb77de30e323fdc3f672..0ef61ea6aa6d11dabbb464bc88a70af401c2afbf 100644
--- a/webrtc/examples/peerconnection/server/data_socket.h
+++ b/webrtc/examples/peerconnection/server/data_socket.h
@@ -8,8 +8,8 @@
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
-#ifndef TALK_EXAMPLES_PEERCONNECTION_SERVER_DATA_SOCKET_H_
-#define TALK_EXAMPLES_PEERCONNECTION_SERVER_DATA_SOCKET_H_
+#ifndef WEBRTC_EXAMPLES_PEERCONNECTION_SERVER_DATA_SOCKET_H_
+#define WEBRTC_EXAMPLES_PEERCONNECTION_SERVER_DATA_SOCKET_H_
 #pragma once
 
 #ifdef WIN32
@@ -150,4 +150,4 @@ class ListeningSocket : public SocketBase {
   DataSocket* Accept() const;
 };
 
-#endif  // TALK_EXAMPLES_PEERCONNECTION_SERVER_DATA_SOCKET_H_
+#endif  // WEBRTC_EXAMPLES_PEERCONNECTION_SERVER_DATA_SOCKET_H_