Move StringToLowerASCII to base namespace

ui/gl/gl_version_info.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 "ui/gl/gl_version_info.h"
 
 #include "base/strings/string_util.h"
 
 namespace gfx {
 
 GLVersionInfo::GLVersionInfo(const char* version_str, const char* renderer_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),
       is_angle(false) {
   if (version_str) {
-    std::string lstr(StringToLowerASCII(std::string(version_str)));
+    std::string lstr(base::StringToLowerASCII(std::string(version_str)));
     is_es = (lstr.substr(0, 9) == "opengl es");
     if (is_es) {
       is_es1 = (lstr.substr(9, 2) == "-c" && lstr.substr(13, 2) == "1.");
       is_es2 = (lstr.substr(9, 3) == " 2.");
       is_es3 = (lstr.substr(9, 3) == " 3.");
     } else {
       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;
     }
   }
   if (renderer_str) {
     is_angle = StartsWithASCII(renderer_str, "ANGLE", true);
   }
 }
 
 }  // namespace gfx