Re-land: gpu: Add CHROMIUM_sync_query extension.

gpu/command_buffer/service/feature_info.cc

Index: gpu/command_buffer/service/feature_info.cc
diff --git a/gpu/command_buffer/service/feature_info.cc b/gpu/command_buffer/service/feature_info.cc
index 334cec172b1cec39f66b8650ed503328e45e4b15..15d8ca0610df61fccef0f8d3cd93e329ef7e6192 100644
--- a/gpu/command_buffer/service/feature_info.cc
+++ b/gpu/command_buffer/service/feature_info.cc
@@ -110,6 +110,7 @@ FeatureInfo::FeatureFlags::FeatureFlags()
     : chromium_color_buffer_float_rgba(false),
       chromium_color_buffer_float_rgb(false),
       chromium_framebuffer_multisample(false),
+      chromium_sync_query(false),
       use_core_framebuffer_multisample(false),
       multisampled_render_to_texture(false),
       use_img_for_multisampled_render_to_texture(false),
@@ -794,6 +795,11 @@ void FeatureInfo::InitializeFeatures() {
     AddExtensionString("GL_EXT_discard_framebuffer");
     feature_flags_.ext_discard_framebuffer = true;
   }
+
+  if (ui_gl_fence_works) {
+    AddExtensionString("GL_CHROMIUM_sync_query");
+    feature_flags_.chromium_sync_query = true;
+  }
 }
 
 void FeatureInfo::AddExtensionString(const std::string& str) {