Load the GL_KHR_debug entry points and log messages they produce.

gpu/command_buffer/service/feature_info.h

Index: gpu/command_buffer/service/feature_info.h
diff --git a/gpu/command_buffer/service/feature_info.h b/gpu/command_buffer/service/feature_info.h
index faf50d353161da544c6ce06b7e6c34bc92d0fdfd..ebc9ca64a16c756c3f558ce4c42e24a0cb84e4e5 100644
--- a/gpu/command_buffer/service/feature_info.h
+++ b/gpu/command_buffer/service/feature_info.h
@@ -95,6 +95,7 @@ class GPU_EXPORT FeatureInfo : public base::RefCounted<FeatureInfo> {
     bool chromium_color_buffer_float_rgb = false;
     bool chromium_color_buffer_float_rgba = false;
     bool angle_robust_client_memory = false;
+    bool khr_debug = false;
   };
 
   FeatureInfo();