Fix gpu mipmap support on ChromeOS

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_number_conversions.h"
 #include "base/strings/string_split.h"
 #include "base/strings/string_tokenizer.h"
 #include "base/strings/string_util.h"
@@ skipping 27 matching lines @@
 GLVersionInfo::GLVersionInfo(const char* version_str,
                              const char* renderer_str,
                              const std::set<std::string>& extensions)
     : GLVersionInfo() {
   Initialize(version_str, renderer_str, extensions);
 }
 
 GLVersionInfo::GLVersionInfo()
     : is_es(false),
       is_angle(false),
+      is_mesa(false),
       major_version(0),
       minor_version(0),
       is_es2(false),
       is_es3(false),
       is_desktop_core_profile(false),
       is_es3_capable(false) {}
 
 void GLVersionInfo::Initialize(const char* version_str,
                                const char* renderer_str,
                                const std::set<std::string>& extensions) {
   if (version_str) {
     ParseVersionString(version_str, &major_version, &minor_version,
                        &is_es, &is_es2, &is_es3);
   }
   if (renderer_str) {
     is_angle = base::StartsWith(renderer_str, "ANGLE",
                                 base::CompareCase::SENSITIVE);
+    is_mesa = base::StartsWith(renderer_str, "Mesa",
+                               base::CompareCase::SENSITIVE);
   }
   is_desktop_core_profile =
       DesktopCoreCommonCheck(is_es, major_version, minor_version) &&
       extensions.find("GL_ARB_compatibility") == extensions.end();
   is_es3_capable = IsES3Capable(extensions);
 }
 
 bool GLVersionInfo::IsES3Capable(
     const std::set<std::string>& extensions) const {
   auto has_extension = [&extensions](std::string extension) -> bool {
@@ skipping 63 matching lines @@
     }
   }
   if (*is_es && *major_version == 2)
     *is_es2 = true;
   if (*is_es && *major_version == 3)
     *is_es3 = true;
   DCHECK(major_version != 0);
 }
 
 }  // namespace gl