Add a new ozone switch to enable surfaceless output mode.

ui/ozone/platform/dri/gbm_surface_factory.h

Index: ui/ozone/platform/dri/gbm_surface_factory.h
diff --git a/ui/ozone/platform/dri/gbm_surface_factory.h b/ui/ozone/platform/dri/gbm_surface_factory.h
index a8a0c4c8cc43e1fa7d61d0aa59d47de89eda5273..b3d15cbc8beeeda41d643741dafbf4d50a31075d 100644
--- a/ui/ozone/platform/dri/gbm_surface_factory.h
+++ b/ui/ozone/platform/dri/gbm_surface_factory.h
@@ -29,6 +29,8 @@ class GbmSurfaceFactory : public DriSurfaceFactory {
       SetGLGetProcAddressProcCallback set_gl_get_proc_address) OVERRIDE;
   virtual scoped_ptr<ui::SurfaceOzoneEGL> CreateEGLSurfaceForWidget(
       gfx::AcceleratedWidget w) OVERRIDE;
+  virtual scoped_ptr<SurfaceOzoneEGL> CreateSurfacelessEGLSurfaceForWidget(
+      gfx::AcceleratedWidget widget) OVERRIDE;
   virtual scoped_refptr<ui::NativePixmap> CreateNativePixmap(
       gfx::Size size,
       BufferFormat format) OVERRIDE;