Fix override warnings.

Bug: webrtc:6306
Change-Id: I5c01139475a75d56a9642943eff527eaf036c738
Reviewed-on: https://webrtc-review.googlesource.com/55522
Reviewed-by: Kári Helgason <kthelgason@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#22126}

examples/BUILD.gn

@@ -528,13 +528,6 @@ if (is_linux || is_win) {
         "-Wno-sentinel",
       ]
     }
-
-    if (is_clang) {
-      # TODO(ehmaldonado): Make peerconnection_client compile with the standard
-      # set of warnings.
-      # See https://bugs.chromium.org/p/webrtc/issues/detail?id=6306
-      cflags += [ "-Wno-inconsistent-missing-override" ]
-    }
   }
 
   rtc_executable("peerconnection_client") {

examples/peerconnection/client/conductor.h

@@ -48,7 +48,7 @@ class Conductor
 
   bool connection_active() const;
 
-  virtual void Close();
+  void Close() override;
 
  protected:
   ~Conductor();

examples/peerconnection/client/linux/main.cc

@@ -32,7 +32,7 @@ class CustomSocketServer : public rtc::PhysicalSocketServer {
   void set_conductor(Conductor* conductor) { conductor_ = conductor; }
 
   // Override so that we can also pump the GTK message loop.
-  virtual bool Wait(int cms, bool process_io) {
+  bool Wait(int cms, bool process_io) override {
     // Pump GTK events.
     // 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