Add a factory and defines for native Linux surfaces.

ui/base/ozone/surface_factory_ozone.cc

+// Copyright (c) 2013 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.
+
+#include "ui/base/ozone/surface_factory_ozone.h"
+
+#include "base/lazy_instance.h"
+#include "base/memory/scoped_ptr.h"
+
+namespace ui {
+
+// Implementation.
+static base::LazyInstance<scoped_ptr<SurfaceFactoryOzone> > impl_ =
+    LAZY_INSTANCE_INITIALIZER;
+
+SurfaceFactoryOzone::SurfaceFactoryOzone() {
+}
+
+SurfaceFactoryOzone::~SurfaceFactoryOzone() {
+}
+
+SurfaceFactoryOzone* SurfaceFactoryOzone::GetInstance() {
+  return impl_.Get().get();
+}
+
+void SurfaceFactoryOzone::SetInstance(SurfaceFactoryOzone* impl) {
+  impl_.Get().reset(impl);
+}
+
+const char* SurfaceFactoryOzone::DefaultDisplaySpec() {
+  char* envvar = getenv("ASH_DISPLAY_SPEC");
+  if (envvar)
+    return envvar;
+  else

[sky, 2013/05/23 23:47:20]

nit: no else (the style guide actually says no else here).

+    return  "720x1280*2";
+}
+
+}  // namespace ui