Take GL version and extensions correctly into account when binding functions

ui/gl/gl_version_info.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_version_info.h"
+
+#include "base/strings/string_util.h"
+
+namespace gfx {
+
+GLVersionInfo::GLVersionInfo(const char* version_str)
+    : is_es(false),
+      is_es1(false),
+      is_es2(false),
+      is_es3(false),
+      is_gl1(false),
+      is_gl2(false),
+      is_gl3(false),
+      is_gl4(false) {
+  if (version_str) {
+    std::string lstr(StringToLowerASCII(std::string(version_str)));
+    is_es1 = (lstr.substr(0, 11) == "opengl es-c" &&
+              lstr.substr(13, 2) == "1.");
+    is_es2 = (lstr.substr(0, 12) == "opengl es 2.");
+    is_es3 = (lstr.substr(0, 12) == "opengl es 3.");
+    is_es = is_es1 || is_es2 || is_es3;
+

[no sievers, 2013/12/05 20:51:57]

nit: if (!is_es) { ...

[oetuaho, 2013/12/09 17:17:07]

I'll restructure this a bit.

+    is_gl2 = (lstr.substr(0, 2) == "2.");
+    is_gl3 = (lstr.substr(0, 2) == "3.");
+    is_gl4 = (lstr.substr(0, 2) == "4.");
+    // In early GL versions, GetString output format is implementation
+    // dependent.
+    is_gl1 = !is_gl2 && !is_gl3 && !is_gl4 && !is_es;
+  }
+}
+
+}  // namespace gfx