Standardize usage of virtual/override/final specifiers.

remoting/host/linux/x_server_clipboard_unittest.cc

Index: remoting/host/linux/x_server_clipboard_unittest.cc
diff --git a/remoting/host/linux/x_server_clipboard_unittest.cc b/remoting/host/linux/x_server_clipboard_unittest.cc
index 57ca4157a2a37d54dcbe29a74f547734569b2897..ea52a07532e111f19e20ae7f95c78b88bfa5967c 100644
--- a/remoting/host/linux/x_server_clipboard_unittest.cc
+++ b/remoting/host/linux/x_server_clipboard_unittest.cc
@@ -67,7 +67,7 @@ class ClipboardTestClient {
 
 class XServerClipboardTest : public testing::Test {
  public:
-  virtual void SetUp() override {
+  void SetUp() override {
     // XSynchronize() ensures that PumpXEvents() fully processes all X server
     // requests and responses before returning to the caller.
     Display* display1 = XOpenDisplay(NULL);
@@ -78,7 +78,7 @@ class XServerClipboardTest : public testing::Test {
     client2_.Init(display2);
   }
 
-  virtual void TearDown() override {
+  void TearDown() override {
     XCloseDisplay(client1_.display());
     XCloseDisplay(client2_.display());
   }