Don't verify PMA in writePixels

[reed1, 2011-12-07 21:59:11]

this may be what is necessary, but boo-hoo: now we have two webkitisms leaking
into our std impl:
1. no check on premul
2. slow as crap / alpha divisions

[bsalomon, 2011-12-08 13:44:44]

On 2011/12/07 21:59:11, reed1 wrote:
> this may be what is necessary, but boo-hoo: now we have two webkitisms leaking
> into our std impl:
> 1. no check on premul

I filed a WK bug against the bad pixels, hopefully it will get fixed and we can
remove the NoCheck. We could add a user config macro that turns on the no check
variant and only define that in chrome's skia.gyp.

> 2. slow as crap / alpha divisions

Because the GPU mul and div round differently than the WK platform code in
ImageBufferSkia we have to add tests to test_expectations anyway. I think we can
feel free to change the SW path as well for better performance.

[bsalomon, 2011-12-08 15:20:22]

closed with 2828