gpu/khronos_glcts_support: add support for GN builds

gpu/khronos_glcts_support/native/egl_native_windowless.cc

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // Using egl_native from gles2_conform_support
 // TODO: We may want to phase out the old gles2_conform support in preference
 // of this implementation.  So eventually we'll need to move the egl_native
 // stuff here or to a shareable location/path.
 #include "gpu/gles2_conform_support/egl/display.h"
 
@@ skipping 10 matching lines @@
           const EGLint* attribList,
           int width,
           int height)
       : tcu::egl::WindowSurface(display,
                                 config,
                                 (EGLNativeWindowType)NULL,
                                 attribList),
         width_(width),
         height_(height) {}
 
-  int getWidth() const { return width_; }
+  int getWidth() const override { return width_; }
 
-  int getHeight() const { return height_; }
+  int getHeight() const override { return height_; }
 
  private:
   const int width_;
   const int height_;
 };
 
 class Window : public tcu::NativeWindow {
  public:
   Window(tcu::egl::Display& display,
          EGLConfig config,
          const EGLint* attribList,
          int width,
          int height)
       : tcu::NativeWindow::NativeWindow(),
         eglDisplay_(display),
         surface_(display, config, attribList, width, height) {}
 
-  virtual ~Window() {}
+  ~Window() override {}
 
-  tcu::egl::Display& getEglDisplay() { return eglDisplay_; }
+  tcu::egl::Display& getEglDisplay() override { return eglDisplay_; }
 
-  tcu::egl::WindowSurface& getEglSurface() { return surface_; }
+  tcu::egl::WindowSurface& getEglSurface() override { return surface_; }
 
-  void processEvents() { return; }
+  void processEvents() override { return; }
 
  private:
   tcu::egl::Display& eglDisplay_;
   Surface surface_;
 };
 
 class Platform : public tcu::EglPlatform {
  public:
   Platform() : tcu::EglPlatform::EglPlatform() {}
 
-  virtual ~Platform() {}
+  ~Platform() override {}
 
   tcu::NativeWindow* createWindow(tcu::NativeDisplay& dpy,
                                   EGLConfig config,
                                   const EGLint* attribList,
                                   int width,
                                   int height,
-                                  qpVisibility visibility) {
+                                  qpVisibility visibility) override {
     tcu::egl::Display& eglDisplay = dpy.getEglDisplay();
     egl::Display* display =
         static_cast<egl::Display*>(eglDisplay.getEGLDisplay());
     display->SetCreateOffscreen(width, height);
     return new Window(eglDisplay, config, attribList, width, height);
   }
 };
 
 }  // namespace windowless
 }  // namespace native
 }  // namespace egl
 
 tcu::Platform* createPlatform(void) {
   return new egl::native::windowless::Platform();
 }