Add a SpinningCube to Mojo's sample_app

We don't actually call this code yet, but we're going to need this code in
order to demo a spinning cube. I've verified that this code draws a cube when
called directly from mojo_shell. It should work when called from sample_app
once we figure out how we want to expose GL to Mojo apps.

R=jamesr@chromium.org

Review URL: https://codereview.chromium.org/61423003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@233309 0039d316-1c4b-4281-b951-d872f2087c98

mojo/examples/sample_app/DEPS

+include_rules = [
+  # TODO(abarth): Rather than including this interface directly,
+  # we need to figure out the right way for apps to call GL.
+  "!gpu/command_buffer/client/gles2_interface.h",
+]

mojo/examples/sample_app/spinning_cube.h

+// Copyright 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.
+
+#ifndef MOJO_EXAMPLES_SAMPLE_APP_SPINNING_CUBE_H_
+#define MOJO_EXAMPLES_SAMPLE_APP_SPINNING_CUBE_H_
+
+#include "base/memory/scoped_ptr.h"
+
+namespace gpu {
+namespace gles2 {
+class GLES2Interface;
+}
+}
+
+namespace mojo {
+namespace examples {
+
+class SpinningCube {
+ public:
+  SpinningCube();
+  ~SpinningCube();
+
+  void BindTo(gpu::gles2::GLES2Interface* gl,
+              int width,
+              int height);
+  void OnGLContextLost();
+
+  void Update(float delta_time);
+  void Draw();
+
+ private:
+  class GLState;
+
+  gpu::gles2::GLES2Interface* gl_;
+  int width_;
+  int height_;
+  scoped_ptr<GLState> state_;
+};
+
+}  // namespace examples
+}  // namespace mojo
+
+#endif  // MOJO_EXAMPLES_SAMPLE_APP_SPINNING_CUBE_H_

mojo/mojo.gyp

@@ -231,10 +231,13 @@
       'target_name': 'sample_app',
       'type': 'shared_library',
       'dependencies': [
+        '../ui/gl/gl.gyp:gl',
         'mojo_system',
       ],
       'sources': [
         'examples/sample_app/sample_app.cc',
+        'examples/sample_app/spinning_cube.cc',
+        'examples/sample_app/spinning_cube.h',
       ],
     },
     {