Revert of Change drawText() to generate positions and send to drawPosText()

Revert of Change drawText() to generate positions and send to drawPosText() (patchset #4 id:60001 of https://codereview.chromium.org/653133004/)

Reason for revert:
A large number of GMs on Ubuntu12 are failing. The text layout on GPU is visibly different than that for 8888.

Original issue's description:
> Change drawText() to generate positions and send to drawPosText()
> 
> The idea here is to have a central place that does layout for drawText(), and
> then always feed text through drawPosText(). This both makes all of the 
> GrTextContexts consistent in drawText() output, and does a better job of
> stressing drawPosText().
> 
> Because of the effect of matrices on hinting and approximation error, the 
> generated text is not 100% identical to that produced by the raster pipeline.
> 
> BUG=skia:2778
> 
> Committed: https://skia.googlesource.com/skia/+/7851a56895c9c076f73a835a7dd51d3c6180c16f

TBR=cdalton.nvidia@gmail.com,bungeman@google.com,reed@google.com
NOTREECHECKS=true
NOTRY=true
BUG=skia:2778
Committed: https://skia.googlesource.com/skia/+/aab626c3670205d02ca42bb34a540f550cb75dc2

[jvanverth1, 2014-10-16 15:04:06]

Created Revert of Change drawText() to generate positions and send to
drawPosText()

[commit-bot: I haz the power, 2014-10-16 15:04:17]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/659993003/1

[commit-bot: I haz the power, 2014-10-16 15:04:45]

Committed patchset #1 (id:1) as aab626c3670205d02ca42bb34a540f550cb75dc2