Add support for GL_*_shader_framebuffer_fetch

Add support for GL_*_shader__framebuffer_fetch

R=robertphillips@google.com

Committed: https://code.google.com/p/skia/source/detail?r=8980

[robertphillips, 2013-05-02 21:22:08]

lgtm

[robertphillips, 2013-05-02 21:22:27]

Any performance numbers on this?

[bsalomon, 2013-05-03 13:32:07]

On 2013/05/02 21:22:27, robertphillips wrote:
> Any performance numbers on this?

On a N7:

PRE:
running bench [640 480]              Xfermode_Darken   GPU: cmsecs =   7.16
running bench [640 480]             Xfermode_SrcOver   GPU: cmsecs =   4.05
running bench [640 480]                 Xfermode_Src   GPU: cmsecs =   4.17

POST:
running bench [640 480]              Xfermode_Darken   GPU: cmsecs =  84.69
running bench [640 480]             Xfermode_SrcOver   GPU: cmsecs =   4.06
running bench [640 480]                 Xfermode_Src   GPU: cmsecs =   4.17

[bsalomon, 2013-05-03 13:33:03]

On 2013/05/03 13:32:07, bsalomon wrote:
> On 2013/05/02 21:22:27, robertphillips wrote:
> > Any performance numbers on this?
> 
> On a N7:
> 
> PRE:
> running bench [640 480]              Xfermode_Darken   GPU: cmsecs =   7.16
> running bench [640 480]             Xfermode_SrcOver   GPU: cmsecs =   4.05
> running bench [640 480]                 Xfermode_Src   GPU: cmsecs =   4.17
> 
> POST:
> running bench [640 480]              Xfermode_Darken   GPU: cmsecs =  84.69
> running bench [640 480]             Xfermode_SrcOver   GPU: cmsecs =   4.06
> running bench [640 480]                 Xfermode_Src   GPU: cmsecs =   4.17

err, reverse that (84.69 msecs before the change).

[bsalomon, 2013-05-03 13:35:18]

Committed patchset #2 manually as r8980 (presubmit successful).