Fix GN build with missing ShaderVars.cpp.

Change-Id: I29be6cdda643f83a40a6adc9b76153667aafcc51
Reviewed-on: https://chromium-review.googlesource.com/211400
Tested-by: Jamie Madill <jmadill@chromium.org>
Reviewed-by: Zhenyao Mo <zmo@chromium.org>
1 file changed