[Ozone] Add Ozone EGL demo

ui/ozone/demo/egl_demo.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.
+
+#include "base/at_exit.h"
+#include "base/command_line.h"
+#include "ui/gfx/geometry/size.h"
+#include "ui/gl/gl_bindings.h"
+#include "ui/gl/gl_context.h"
+#include "ui/gl/gl_surface.h"
+#include "ui/ozone/ozone_platform.h"
+#include "ui/ozone/public/surface_factory_ozone.h"
+
+int main(int argc, char** argv) {
+  CommandLine::Init(argc, argv);
+  base::AtExitManager exit_manager;
+
+  ui::OzonePlatform::InitializeForUI();
+  if (!gfx::GLSurface::InitializeOneOff()) {
+    LOG(ERROR) << "Failed to initialize GL";
+    return 1;
+  }
+
+  gfx::AcceleratedWidget widget =
+      ui::SurfaceFactoryOzone::GetInstance()->GetAcceleratedWidget();
+  scoped_refptr<gfx::GLSurface> surface =
+      gfx::GLSurface::CreateViewGLSurface(widget);

[spang, 2014/07/03 18:33:23]

this can fail.

[dnicoara, 2014/07/03 18:51:36]

Done.

+  scoped_refptr<gfx::GLContext> context = gfx::GLContext::CreateGLContext(
+      NULL, surface.get(), gfx::PreferIntegratedGpu);

[spang, 2014/07/03 18:33:23]

also can fail.

[dnicoara, 2014/07/03 18:51:36]

Done.

+
+  const gfx::Size window_size(800, 600);
+  int iterations = 120;
+
+  surface->Resize(window_size);
+  context->MakeCurrent(surface.get());

[spang, 2014/07/03 18:33:23]

can fail.

[dnicoara, 2014/07/03 18:51:36]

Done.

+
+  for (int i = 0; i < iterations; ++i) {
+    glViewport(0, 0, window_size.width(), window_size.height());
+    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
+    float fraction = static_cast<float>(i) / iterations;
+    glClearColor(1 - fraction, fraction, 0.0, 1.0);
+
+    if (!surface->SwapBuffers()) {
+      LOG(ERROR) << "Failed to swap buffers";

[spang, 2014/07/03 18:33:23]

maybe just LOG(FATAL) ?

[dnicoara, 2014/07/03 18:51:36]

Done.

+      return 1;
+    }
+  }
+
+  return 0;
+}