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;
 }
diff --git a/webrtc/examples/peerconnection/client/linux/main_wnd.cc b/webrtc/examples/peerconnection/client/linux/main_wnd.cc
index 254fb94..cf98c1c 100644
--- a/webrtc/examples/peerconnection/client/linux/main_wnd.cc
+++ b/webrtc/examples/peerconnection/client/linux/main_wnd.cc
@@ -116,7 +116,8 @@
   wnd->OnRedraw();
   return false;
 }
-}  // end anonymous
+
+}  // namespace
 
 //
 // GtkMainWnd implementation.
@@ -174,7 +175,8 @@
   local_renderer_.reset();
 }
 
-void GtkMainWnd::StartRemoteRenderer(webrtc::VideoTrackInterface* remote_video) {
+void GtkMainWnd::StartRemoteRenderer(
+    webrtc::VideoTrackInterface* remote_video) {
   remote_renderer_.reset(new VideoRenderer(this, remote_video));
 }
 
@@ -488,7 +490,7 @@
           static_cast<int>(frame->GetHeight()));
 
   int size = width_ * height_ * 4;
-  // TODO: Convert directly to RGBA
+  // TODO(henrike): Convert directly to RGBA
   frame->ConvertToRgbBuffer(cricket::FOURCC_ARGB,
                             image_.get(),
                             size,
diff --git a/webrtc/examples/peerconnection/client/linux/main_wnd.h b/webrtc/examples/peerconnection/client/linux/main_wnd.h
index 1a91082..e35d4dd 100644
--- a/webrtc/examples/peerconnection/client/linux/main_wnd.h
+++ b/webrtc/examples/peerconnection/client/linux/main_wnd.h
@@ -8,8 +8,10 @@
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
-#ifndef PEERCONNECTION_SAMPLES_CLIENT_LINUX_MAIN_WND_H_
-#define PEERCONNECTION_SAMPLES_CLIENT_LINUX_MAIN_WND_H_
+#ifndef WEBRTC_EXAMPLES_PEERCONNECTION_CLIENT_LINUX_MAIN_WND_H_
+#define WEBRTC_EXAMPLES_PEERCONNECTION_CLIENT_LINUX_MAIN_WND_H_
+
+#include <string>
 
 #include "webrtc/examples/peerconnection/client/main_wnd.h"
 #include "webrtc/examples/peerconnection/client/peer_connection_client.h"
@@ -115,4 +117,4 @@
   int draw_buffer_size_;
 };
 
-#endif  // PEERCONNECTION_SAMPLES_CLIENT_LINUX_MAIN_WND_H_
+#endif  // WEBRTC_EXAMPLES_PEERCONNECTION_CLIENT_LINUX_MAIN_WND_H_