SkPaintFilterCanvas should inherit the target canvas state

SkPaintFilterCanvas should inherit the target canvas state

Currently, SkPaintFilterCanvas does not provide any help in cloning
target canvas state.  While that could be handled in subclasses, it is
easy to miss (see linked bug).

This CL adds a new constructor variant which ensures that the initial
matrix and clip bounds are inherited from the target canvas.

BUG=516790
R=reed@google.com,robertphillips@google.com

Committed: https://skia.googlesource.com/skia/+/f433bb2bebd441cc0b2b152e8fbf79eac43baf5d

[f(malita), 2015-08-16 08:34:12]

The CQ bit was checked by fmalita@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2015-08-16 08:34:23]

Dry run: CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1294013002/40001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1294013002/40001

[commit-bot: I haz the power, 2015-08-16 08:40:23]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2015-08-16 08:40:23]

Dry run: This issue passed the CQ dry run.

[f(malita), 2015-08-17 14:00:47]

fmalita@chromium.org changed reviewers:
+ mtklein@google.com

[reed1, 2015-08-17 14:44:24]

lgtm

is the intended client chrome?

[f(malita), 2015-08-17 14:51:46]

On 2015/08/17 14:44:24, reed1 wrote:
> lgtm
> 
> is the intended client chrome?

Yes, that's where the missing state problem surfaced (OpacityFilterCanvas). 
Rather than fixing this one client at a time, I figured we should handle it in
the base class - so I think all SkPaintFilterCanvas clients should switch to the
new constructor (Skia debugger being the only other one I know of).

[f(malita), 2015-08-17 14:59:06]

The CQ bit was checked by fmalita@chromium.org

[commit-bot: I haz the power, 2015-08-17 14:59:13]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1294013002/40001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1294013002/40001

[commit-bot: I haz the power, 2015-08-17 15:05:16]

Committed patchset #3 (id:40001) as
https://skia.googlesource.com/skia/+/f433bb2bebd441cc0b2b152e8fbf79eac43baf5d