update android port

[aydinkim]

Pre-works for upgrading androidport of Servo.
Implement newer rendering structure for CPU and GPU on android.

[aydinkim]

Modified the API name to call. Mr. recrack had changed the PR in rust-opengles.

[aydinkim]

@metajack How about this related to fragment shader?
https://github.com/webconvforge/rust-layers/commit/77b407adcaaf570ea6e3f98c618f81e009dfb065

[aydinkim]

I fixed rendergl.rs in order to keep original shader source code to be correct.
I wrapped render context with Option so that we can pass only 2d shader on android.
Plz take a look and review it.

p.s> 8750941 is a hot fix of aeba4f4 above. I can merge them into one if you want.

[aydinkim]

@metajack How about this works? I'm curious this is acceptable or not.

[metajack]

It's acceptable assuming we don't need to switch back and forth.

[metajack]

And if we don't need to switch back and forth, why have both programs?

[aydinkim]

Squashed.

[metajack]

I'll merge this when build changes land.

[aydinkim]

No problem!