Standardize usage of virtual/override/final specifiers.

extensions/shell/browser/shell_desktop_controller_unittest.cc

Index: extensions/shell/browser/shell_desktop_controller_unittest.cc
diff --git a/extensions/shell/browser/shell_desktop_controller_unittest.cc b/extensions/shell/browser/shell_desktop_controller_unittest.cc
index e43eafb3b9c429aac724e7bbb21ff12104201e56..5972d580b1b130795a28232df6324819e6315e62 100644
--- a/extensions/shell/browser/shell_desktop_controller_unittest.cc
+++ b/extensions/shell/browser/shell_desktop_controller_unittest.cc
@@ -24,9 +24,9 @@ class ShellDesktopControllerTest : public aura::test::AuraTestBase {
 #endif
       {
   }
-  virtual ~ShellDesktopControllerTest() {}
+  ~ShellDesktopControllerTest() override {}
 
-  virtual void SetUp() override {
+  void SetUp() override {
 #if defined(OS_CHROMEOS)
     scoped_ptr<chromeos::DBusThreadManagerSetter> dbus_setter =
         chromeos::DBusThreadManager::GetSetterForTesting();
@@ -37,7 +37,7 @@ class ShellDesktopControllerTest : public aura::test::AuraTestBase {
     controller_.reset(new ShellDesktopController());
   }
 
-  virtual void TearDown() override {
+  void TearDown() override {
     controller_.reset();
     aura::test::AuraTestBase::TearDown();
 #if defined(OS_CHROMEOS)