[cairo] [path] cache uniforms

[Martin Robinson]

On 06/13/2013 02:52 PM, Henry (Yu) Song - SISA wrote:
> On mobile drivers, where a typical glGetUniform takes 2 – 3
> microseconds.  This is called possibly multiple times for each drawing
> operation.  Saving uniform locations reduces time.

Since a very similar patch by Eric was landed as
7b8fc77bb974fbd4fbc697405a8b6aec748bb7f2, I guess this one can be discarded.

--Martin