Conflict does not always have to be negative. The key is to speak truth in love.
I'm not talking about when your girlfriend asks if the dress makes her look fat, and you think "Well, I love her so I better tell her the truth."
I'm thinking about when the same girlfriend plays Words with Friends while you're telling her about the specs of the new HVAC system you're designing. Obviously you know she doesn't really care about HVAC, but it hurts your feelings anyway that she won't give you her attention for just a few minutes.
The conflict is not her commitment to her game, but your inability to tell her that you're hurt. From that pain often comes the sideways anger that happens when she wants to tell you about her successful conquest for the pearl flats and you don't look up from your screen.
You think, "Why should I listen when she didn't?"
So do you love her enough to speak the truth? The truth is not that you want her to stop playing the game. Nor is it that you want her to be passionate about HVAC. The truth is that you want her to love you enough to give you attention and you have to tell her.
It might be uncomfortable, and she might be defensive, but one of two things will happen; the relationship will grow, or the hard truth will come out - that she does not love you enough to communicate through conflict.