Take GL version and extensions correctly into account when binding functions

ui/gl/gl_context_mock_version.h

+// 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.
+
+#ifndef UI_GL_GL_CONTEXT_MOCK_VERSION_H_
+#define UI_GL_GL_CONTEXT_MOCK_VERSION_H_
+
+#include "ui/gl/gl_context_stub.h"
+
+namespace gfx {
+
+// A GLContext that only reports its version for unit tests.
+class GL_EXPORT GLContextMockVersion : public GLContextStub {
+ public:
+  explicit GLContextMockVersion(const char* version_str);
+
+ protected:
+  virtual std::string GetGLVersion() OVERRIDE;
+
+  virtual ~GLContextMockVersion();
+
+ private:
+  const char* version_str_;
+
+  DISALLOW_COPY_AND_ASSIGN(GLContextMockVersion);
+};
+
+}  // namespace gfx
+
+#endif  // UI_GL_GL_CONTEXT_MOCK_VERSION_H_