SkyShell should be able to draw a green square with GL

sky/shell/gpu_driver.cc

+// 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.
+
+#include "sky/shell/gpu_driver.h"
+
+#include "ui/gl/gl_bindings.h"
+#include "ui/gl/gl_context.h"
+#include "ui/gl/gl_share_group.h"
+#include "ui/gl/gl_surface.h"
+
+namespace sky {
+namespace shell {
+
+GPUDriver::GPUDriver() : weak_factory_(this) {
+}
+
+GPUDriver::~GPUDriver() {
+}
+
+base::WeakPtr<GPUDriver> GPUDriver::GetWeakPtr() {
+  return weak_factory_.GetWeakPtr();
+}
+
+void GPUDriver::Init(gfx::AcceleratedWidget widget) {
+  share_group_ = make_scoped_refptr(new gfx::GLShareGroup());
+
+  surface_ = gfx::GLSurface::CreateViewGLSurface(widget);
+  CHECK(surface_) << "GLSurface required.";
+
+  context_ = gfx::GLContext::CreateGLContext(share_group_.get(), surface_.get(),
+                                             gfx::PreferIntegratedGpu);
+  CHECK(context_) << "GLContext required.";
+
+  CHECK(context_->MakeCurrent(surface_.get()));
+
+  glClearColor(0.0, 1.0, 0.0, 0.0);
+  glClear(GL_COLOR_BUFFER_BIT);
+
+  surface_->SwapBuffers();
+}
+
+}  // namespace shell
+}  // namespace sky