Add GL_CHROMIUM_screen_space_antialiasing to support alternative AA

gpu/command_buffer/service/gles2_cmd_decoder_autogen.h

Index: gpu/command_buffer/service/gles2_cmd_decoder_autogen.h
diff --git a/gpu/command_buffer/service/gles2_cmd_decoder_autogen.h b/gpu/command_buffer/service/gles2_cmd_decoder_autogen.h
index b8bb7c15e918813b7c5f836267b9a4e9e8e8776c..62b6dbc5f3c7fdfcb62f7e52f202f56ddcedef05 100644
--- a/gpu/command_buffer/service/gles2_cmd_decoder_autogen.h
+++ b/gpu/command_buffer/service/gles2_cmd_decoder_autogen.h
@@ -5066,6 +5066,24 @@ error::Error GLES2DecoderImpl::HandleBlendBarrierKHR(
   return error::kNoError;
 }
 
+error::Error GLES2DecoderImpl::HandleApplyScreenSpaceAntialiasingCHROMIUM(
+    uint32_t immediate_data_size,
+    const void* cmd_data) {
+  const gles2::cmds::ApplyScreenSpaceAntialiasingCHROMIUM& c =
+      *static_cast<const gles2::cmds::ApplyScreenSpaceAntialiasingCHROMIUM*>(
+          cmd_data);
+  (void)c;
+  if (!features().chromium_screen_space_antialiasing) {
+    LOCAL_SET_GL_ERROR(GL_INVALID_OPERATION,
+                       "glApplyScreenSpaceAntialiasingCHROMIUM",
+                       "function not available");
+    return error::kNoError;
+  }
+
+  DoApplyScreenSpaceAntialiasingCHROMIUM();
+  return error::kNoError;
+}
+
 bool GLES2DecoderImpl::SetCapabilityState(GLenum cap, bool enabled) {
   switch (cap) {
     case GL_BLEND: