SkyShell should be able to draw a green square with GL

sky/shell/gpu_driver.h

+// Copyright 2015 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.
+
+#ifndef SKY_SHELL_GPU_DRIVER_H_
+#define SKY_SHELL_GPU_DRIVER_H_
+
+#include "base/memory/ref_counted.h"
+#include "base/memory/weak_ptr.h"
+#include "ui/gfx/native_widget_types.h"
+
+namespace gfx {
+class GLContext;
+class GLShareGroup;
+class GLSurface;
+}
+
+namespace sky {
+namespace shell {
+
+class GPUDriver {
+ public:
+  explicit GPUDriver();
+  ~GPUDriver();
+
+  base::WeakPtr<GPUDriver> GetWeakPtr();
+
+  void Init(gfx::AcceleratedWidget widget);
+
+ private:
+  scoped_refptr<gfx::GLShareGroup> share_group_;
+  scoped_refptr<gfx::GLSurface> surface_;
+  scoped_refptr<gfx::GLContext> context_;
+
+  base::WeakPtrFactory<GPUDriver> weak_factory_;
+
+  DISALLOW_COPY_AND_ASSIGN(GPUDriver);
+};
+
+}  // namespace shell
+}  // namespace sky
+
+#endif  // SKY_SHELL_GPU_DRIVER_H_