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

BUG=webrtc:5273
TESTED=Fixed issues reported by:
find webrtc/examples/ -type f -name *.cc -o -name *.h | grep -v objc | xargs cpplint.py
followed by 'git cl presubmit'.

NOTRY=True

Review URL: https://codereview.webrtc.org/1504283004

Cr-Commit-Position: refs/heads/master@{#10960}
diff --git a/webrtc/examples/peerconnection/server/data_socket.h b/webrtc/examples/peerconnection/server/data_socket.h
index 454ad39..0ef61ea 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 @@
   DataSocket* Accept() const;
 };
 
-#endif  // TALK_EXAMPLES_PEERCONNECTION_SERVER_DATA_SOCKET_H_
+#endif  // WEBRTC_EXAMPLES_PEERCONNECTION_SERVER_DATA_SOCKET_H_
diff --git a/webrtc/examples/peerconnection/server/peer_channel.cc b/webrtc/examples/peerconnection/server/peer_channel.cc
index 150e5de..5e173cd 100644
--- a/webrtc/examples/peerconnection/server/peer_channel.cc
+++ b/webrtc/examples/peerconnection/server/peer_channel.cc
@@ -19,6 +19,7 @@
 #include "webrtc/examples/peerconnection/server/data_socket.h"
 #include "webrtc/examples/peerconnection/server/utils.h"
 #include "webrtc/base/stringutils.h"
+#include "webrtc/base/urlencode.h"
 
 using rtc::sprintfn;
 
@@ -59,7 +60,7 @@
   assert(socket);
   assert(socket->method() == DataSocket::GET);
   assert(socket->PathEquals("/sign_in"));
-  name_ = socket->request_arguments();  // TODO: urldecode
+  name_ = rtc::UrlDecodeString(socket->request_arguments());
   if (name_.empty())
     name_ = "peer_" + int2str(id_);
   else if (name_.length() > kMaxNameLength)
diff --git a/webrtc/examples/peerconnection/server/peer_channel.h b/webrtc/examples/peerconnection/server/peer_channel.h
index 263f17d..6fd740d 100644
--- a/webrtc/examples/peerconnection/server/peer_channel.h
+++ b/webrtc/examples/peerconnection/server/peer_channel.h
@@ -8,8 +8,8 @@
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
-#ifndef TALK_EXAMPLES_PEERCONNECTION_SERVER_PEER_CHANNEL_H_
-#define TALK_EXAMPLES_PEERCONNECTION_SERVER_PEER_CHANNEL_H_
+#ifndef WEBRTC_EXAMPLES_PEERCONNECTION_SERVER_PEER_CHANNEL_H_
+#define WEBRTC_EXAMPLES_PEERCONNECTION_SERVER_PEER_CHANNEL_H_
 #pragma once
 
 #include <time.h>
@@ -117,4 +117,4 @@
   Members members_;
 };
 
-#endif  // TALK_EXAMPLES_PEERCONNECTION_SERVER_PEER_CHANNEL_H_
+#endif  // WEBRTC_EXAMPLES_PEERCONNECTION_SERVER_PEER_CHANNEL_H_
diff --git a/webrtc/examples/peerconnection/server/utils.h b/webrtc/examples/peerconnection/server/utils.h
index e70968b..e1c8729 100644
--- a/webrtc/examples/peerconnection/server/utils.h
+++ b/webrtc/examples/peerconnection/server/utils.h
@@ -8,8 +8,8 @@
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
-#ifndef TALK_EXAMPLES_PEERCONNECTION_SERVER_UTILS_H_
-#define TALK_EXAMPLES_PEERCONNECTION_SERVER_UTILS_H_
+#ifndef WEBRTC_EXAMPLES_PEERCONNECTION_SERVER_UTILS_H_
+#define WEBRTC_EXAMPLES_PEERCONNECTION_SERVER_UTILS_H_
 #pragma once
 
 #include <assert.h>
@@ -22,4 +22,4 @@
 std::string int2str(int i);
 std::string size_t2str(size_t i);
 
-#endif  // TALK_EXAMPLES_PEERCONNECTION_SERVER_UTILS_H_
+#endif  // WEBRTC_EXAMPLES_PEERCONNECTION_SERVER_UTILS_H_