[M45] SkPaintFilterCanvas should inherit the target canvas state

[M45] SkPaintFilterCanvas should inherit the target canvas state

Cherry-pick of http://crrev.com/1294013002 for M45.

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
TBR=reed@google.com,robertphillips@google.com
NOTREECHECKS=true
NOTRY=true
NOPRESUBMIT=true

Committed: https://skia.googlesource.com/skia/+/7dcc609c3adb8077583b8b70dece697eeae5c574

[f(malita), 2015-08-20 22:21:58]

The CQ bit was checked by fmalita@chromium.org

[commit-bot: I haz the power, 2015-08-20 22:22:25]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1302173002/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1302173002/1

[commit-bot: I haz the power, 2015-08-20 22:22:26]

Note for Reviewers:
The CQ is waiting for an approval.
If you believe that the CL is not ready yet, or if you would like to L-G-T-M
with comments then please uncheck the CQ checkbox.

Waiting for LGTM from valid reviewer(s) till 2015-08-21 04:22 UTC

[f(malita), 2015-08-20 22:26:45]

The CQ bit was unchecked by fmalita@chromium.org

[f(malita), 2015-08-20 22:28:33]

The CQ bit was checked by fmalita@chromium.org

[commit-bot: I haz the power, 2015-08-20 22:28:53]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1302173002/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1302173002/1

[commit-bot: I haz the power, 2015-08-20 22:29:02]

Committed patchset #1 (id:1) as
https://skia.googlesource.com/skia/+/7dcc609c3adb8077583b8b70dece697eeae5c574