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

ui/gl/gl_surface_ozone.cc

Index: ui/gl/gl_surface_ozone.cc
diff --git a/ui/gl/gl_surface_ozone.cc b/ui/gl/gl_surface_ozone.cc
index 7b73d4839ab8feaf391364957eebe19b44da3fa0..400c06c924d551f18f0157035c070547a846f83f 100644
--- a/ui/gl/gl_surface_ozone.cc
+++ b/ui/gl/gl_surface_ozone.cc
@@ -60,7 +60,7 @@ class GL_EXPORT GLSurfaceOzoneEGL : public NativeViewGLSurfaceEGL {
  private:
   using NativeViewGLSurfaceEGL::Initialize;
 
-  virtual ~GLSurfaceOzoneEGL() {
+  ~GLSurfaceOzoneEGL() override {
     Destroy();  // EGL surface must be destroyed before SurfaceOzone
   }
 
@@ -144,7 +144,7 @@ class GL_EXPORT GLSurfaceOzoneSurfaceless : public SurfacelessEGL {
   }
 
  private:
-  virtual ~GLSurfaceOzoneSurfaceless() {
+  ~GLSurfaceOzoneSurfaceless() override {
     Destroy();  // EGL surface must be destroyed before SurfaceOzone
   }