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/client/linux/main.cc b/webrtc/examples/peerconnection/client/linux/main.cc
index cf88c36..4db929c 100644
--- a/webrtc/examples/peerconnection/client/linux/main.cc
+++ b/webrtc/examples/peerconnection/client/linux/main.cc
@@ -30,7 +30,7 @@
   // Override so that we can also pump the GTK message loop.
   virtual bool Wait(int cms, bool process_io) {
     // Pump GTK events.
-    // TODO: We really should move either the socket server or UI to a
+    // TODO(henrike): We really should move either the socket server or UI to a
     // different thread.  Alternatively we could look at merging the two loops
     // by implementing a dispatcher for the socket server and/or use
     // g_main_context_set_poll_func.
@@ -96,10 +96,12 @@
   wnd.Destroy();
 
   thread->set_socketserver(NULL);
-  // TODO: Run the Gtk main loop to tear down the connection.
-  //while (gtk_events_pending()) {
-  //  gtk_main_iteration();
-  //}
+  // TODO(henrike): Run the Gtk main loop to tear down the connection.
+  /*
+  while (gtk_events_pending()) {
+    gtk_main_iteration();
+  }
+  */
   rtc::CleanupSSL();
   return 0;
 }