Check for some extensions before calling potentially NULL GL entry points.

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 981fc05df4a86cb8a195ddc9c454922cda8c10db..44a0d50a2dd11da91e3c0411aa89e577ff88c1be 100644
--- a/gpu/command_buffer/service/feature_info.h
+++ b/gpu/command_buffer/service/feature_info.h
@@ -102,6 +102,10 @@ class GPU_EXPORT FeatureInfo : public base::RefCounted<FeatureInfo> {
     bool angle_webgl_compatibility = false;
     bool ext_srgb_write_control = false;
     bool ext_srgb = false;
+    bool chromium_copy_texture = false;
+    bool chromium_copy_compressed_texture = false;
+    bool angle_framebuffer_multisample = false;
+    bool ext_disjoint_timer_query = false;
   };
 
   FeatureInfo();