Standardize usage of virtual/override/final in ipc/

ipc/ipc_channel_factory.cc

Index: ipc/ipc_channel_factory.cc
diff --git a/ipc/ipc_channel_factory.cc b/ipc/ipc_channel_factory.cc
index f553203b1238cdc8ff2b78f913714afd03b7e6fe..c8431c091c8ba87b13f8f5d08caac3f28fd47a03 100644
--- a/ipc/ipc_channel_factory.cc
+++ b/ipc/ipc_channel_factory.cc
@@ -15,12 +15,11 @@ class PlatformChannelFactory : public ChannelFactory {
       : handle_(handle), mode_(mode) {
   }
 
-  virtual std::string GetName() const override {
+  std::string GetName() const override {
     return handle_.name;
   }
 
-  virtual scoped_ptr<Channel> BuildChannel(
-      Listener* listener) override {
+  scoped_ptr<Channel> BuildChannel(Listener* listener) override {
     return Channel::Create(handle_, mode_, listener);
   }