Re-land: gpu: Add CHROMIUM_sync_query extension.

gpu/command_buffer/service/feature_info.cc

 // Copyright (c) 2012 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 "gpu/command_buffer/service/feature_info.h"
 
 #include <set>
 
 #include "base/command_line.h"
 #include "base/macros.h"
@@ skipping 759 matching lines @@
     // TODO(dsinclair): Add AddExtensionString("GL_CHROMIUM_sampler_objects")
     // when available.
   }
 
   if ((is_es3 || extensions.Contains("GL_EXT_discard_framebuffer")) &&
       !workarounds_.disable_ext_discard_framebuffer) {
     // DiscardFramebufferEXT is automatically bound to InvalidateFramebuffer.
     AddExtensionString("GL_EXT_discard_framebuffer");
     feature_flags_.ext_discard_framebuffer = true;
   }
+
+  if (ui_gl_fence_works)
+    AddExtensionString("GL_CHROMIUM_sync_query");
 }
 
 void FeatureInfo::AddExtensionString(const std::string& str) {
   size_t pos = extensions_.find(str);
   while (pos != std::string::npos &&
          pos + str.length() < extensions_.length() &&
          extensions_.substr(pos + str.length(), 1) != " ") {
     // This extension name is a substring of another.
     pos = extensions_.find(str, pos + str.length());
   }
   if (pos == std::string::npos) {
     extensions_ += (extensions_.empty() ? "" : " ") + str;
   }
 }
 
 FeatureInfo::~FeatureInfo() {
 }
 
 }  // namespace gles2
 }  // namespace gpu