Remove unsafe mode to enable es3 api by default for WebGL2 and ES3 context

gpu/command_buffer/service/gpu_preferences.h

Index: gpu/command_buffer/service/gpu_preferences.h
diff --git a/gpu/command_buffer/service/gpu_preferences.h b/gpu/command_buffer/service/gpu_preferences.h
index 1f3a80dc0124767192e4dfd394fed1fa1bab35f6..05801ab779bf947950a70e64a09c174741507cf1 100644
--- a/gpu/command_buffer/service/gpu_preferences.h
+++ b/gpu/command_buffer/service/gpu_preferences.h
@@ -131,9 +131,6 @@ struct GPU_EXPORT GpuPreferences {
   // Turns on calling TRACE for every GL call.
   bool enable_gpu_service_tracing = false;
 
-  // Enable OpenGL ES 3 APIs without proper service side validation.
-  bool enable_unsafe_es3_apis = false;
-
   // Use the Pass-through command decoder, skipping all validation and state
   // tracking.
   bool use_passthrough_cmd_decoder = false;