Revert of Fix SkTextBlob offset semantics.

Revert of Fix SkTextBlob offset semantics. (patchset #2 id:20001 of https://codereview.chromium.org/605533002/)

Reason for revert:
Breaking the Chrome builds with the error:

[14:54:14.317833] ../../skia/ext/pixel_ref_utils.cc:221:16: error: 'drawPosText' marked 'override' but does not override any member functions
[14:54:14.318022]   virtual void drawPosText(const SkDraw& draw,
[14:54:14.318082]                ^

Original issue's description:
> Fix SkTextBlob offset semantics.
> 
> Implement proper x/y drawTextBlob() handling by plumbing a
> drawPosText() offset parameter (to act as an additional glyph pos
> translation) throughout the device layer.
> 
> The new offset superceeds the existing constY, with a minor semantic
> tweak: whereas previous implementations were ignoring constY in 2D
> positioning mode (scalarsPerGlyph == 2), now the offset is always
> observed, in all positioning modes. We can do this because existing
> drawPosText() clients always pass constY == 0 for full positioning mode.
> 
> R=reed@google.com, jvanverth@google.com, robertphillips@google.com
> 
> Committed: https://skia.googlesource.com/skia/+/c13bc571d3e61a43b87eb97f0719abd304cafaf2

TBR=jvanverth@google.com,reed@google.com,bsalomon@google.com,fmalita@chromium.org
NOTREECHECKS=true
NOTRY=true

Committed: https://skia.googlesource.com/skia/+/d46b8d2bab7cfba8458432248e1568ac377429e9

[robertphillips, 2014-09-29 11:48:09]

Created Revert of Fix SkTextBlob offset semantics.

[commit-bot: I haz the power, 2014-09-29 11:48:36]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/609223003/1

[commit-bot: I haz the power, 2014-09-29 11:48:57]

Committed patchset #1 (id:1) as d46b8d2bab7cfba8458432248e1568ac377429e9

[f(malita), 2014-09-29 13:28:38]

A revert of this CL (patchset #1 id:1) has been created in
https://codereview.chromium.org/607413003/ by fmalita@chromium.org.

The reason for reverting is: Re-landing: Chromium-side fix to be landed with the
roll (https://codereview.chromium.org/607853003/).