virtual/override specifier cleanup in ui/ (mostly Ozone code).

ui/compositor/test/test_compositor_host_ozone.cc

Index: ui/compositor/test/test_compositor_host_ozone.cc
diff --git a/ui/compositor/test/test_compositor_host_ozone.cc b/ui/compositor/test/test_compositor_host_ozone.cc
index b432ab786aea36a652848e9c86e6a3c4c7c33349..f0437d9da48d39c1cdaedefdfc875c3cc00c2c16 100644
--- a/ui/compositor/test/test_compositor_host_ozone.cc
+++ b/ui/compositor/test/test_compositor_host_ozone.cc
@@ -20,12 +20,12 @@ class TestCompositorHostOzone : public TestCompositorHost {
  public:
   TestCompositorHostOzone(const gfx::Rect& bounds,
                           ui::ContextFactory* context_factory);
-  virtual ~TestCompositorHostOzone();
+  ~TestCompositorHostOzone() override;
 
  private:
   // Overridden from TestCompositorHost:
-  virtual void Show() override;
-  virtual ui::Compositor* GetCompositor() override;
+  void Show() override;
+  ui::Compositor* GetCompositor() override;
 
   void Draw();