Revert of Fix recursive computation of filter bounds for drop shadow,

Revert of Fix recursive computation of filter bounds for drop shadow, (patchset #1 of https://codereview.chromium.org/481273005/)

Reason for revert:
This CL is currently breaking the Win7 and Win8 bots on some of the new tests (in DM).

Original issue's description:
> Fix recursive computation of filter bounds for drop shadow,
> morphology, blur.
> 
> Because we're computing "backwards" from a clip rect of destination
> pixels to be filled to the required source pixels, we should use tail
> recursion rather than head recursion in onFilterBounds().
> 
> This actually only makes a difference for drop-shadow, where
> the computation is non-commutative. Blur and morphology commute, but I
> moved them to tail recursion anyway for clarity (so all onFilterBounds
> use tail recursion).
> 
> BUG=skia:
> 
> Committed: https://skia.googlesource.com/skia/+/28648fe4a69b0cee8df42b5966e4e645c3aabefb

TBR=bsalomon@google.com,senorblanco@chromium.org
NOTREECHECKS=true
NOTRY=true
BUG=skia:

Committed: https://skia.googlesource.com/skia/+/38cb688bd0e17021bb140bbc15ac1a7b8f182939

[djsollen, 2014-08-25 16:05:30]

Created Revert of Fix recursive computation of filter bounds for drop shadow,

[commit-bot: I haz the power, 2014-08-25 16:06:15]

CQ is trying da patch. Follow status at
 https://skia-tree-status.appspot.com/cq/djsollen@google.com/504773003/1

[commit-bot: I haz the power, 2014-08-25 16:06:25]

Committed patchset #1 (1) as 38cb688bd0e17021bb140bbc15ac1a7b8f182939