Take GL version and extensions correctly into account when binding functions

ui/gl/gl_context_stub_with_extensions.cc

+// 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.
+
+#include "ui/gl/gl_context_stub_with_extensions.h"
+
+namespace gfx {
+
+void GLContextStubWithExtensions::AddExtensionsString(const char* extensions) {
+  if (extensions == NULL)
+    return;
+
+  if (extensions_.size() != 0)
+    extensions_ += ' ';
+  extensions_ += extensions;
+}
+
+std::string GLContextStubWithExtensions::GetExtensions() {
+  return extensions_;
+}
+
+void GLContextStubWithExtensions::SetGLVersionString(const char* version_str) {
+  version_str_ = std::string(version_str ? version_str : "");
+}
+
+std::string GLContextStubWithExtensions::GetGLVersion() {
+  return version_str_;
+}
+
+}  // namespace gfx