Add unit test for SkDashPathEffect::asPoints' culling

Add unit test for SkDashPathEffect::asPoints' culling

This is a follow on to (Crop the fast path dashed lines to the cull rect - https://codereview.chromium.org/699623003/)

Committed: https://skia.googlesource.com/skia/+/2b9ee63c2423167cf39d7a5027db944057c74cfd

[robertphillips, 2014-11-05 14:18:08]

robertphillips@google.com changed reviewers:
+ egdaniel@google.com, reed@google.com

[robertphillips, 2014-11-05 14:18:33]

robertphillips@google.com changed reviewers:
+ danakj@chromium.org

[robertphillips, 2014-11-05 15:38:25]

PTAL. This version adds:

4 new test cases that straddle just the LTRB edges
alternation of the start & end points

[egdaniel, 2014-11-05 15:50:13]

lgtm

[robertphillips, 2014-11-05 15:52:36]

The CQ bit was checked by robertphillips@google.com

[commit-bot: I haz the power, 2014-11-05 15:52:56]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/701133002/20001

[commit-bot: I haz the power, 2014-11-05 15:54:17]

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

[commit-bot: I haz the power, 2014-11-05 15:54:18]

Try jobs failed on following builders:
  Build-Ubuntu13.10-Clang-x86_64-Debug-Trybot on client.skia.compile
(http://build.chromium.org/p/client.skia.compile/builders/Build-Ubuntu13.10-Cl...)
  Build-Ubuntu13.10-GCC4.8-x86_64-Release-Trybot on client.skia.compile
(http://build.chromium.org/p/client.skia.compile/builders/Build-Ubuntu13.10-GC...)

[robertphillips, 2014-11-05 15:57:24]

The CQ bit was checked by robertphillips@google.com

[commit-bot: I haz the power, 2014-11-05 15:57:56]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/701133002/40001

[commit-bot: I haz the power, 2014-11-05 16:06:47]

Committed patchset #3 (id:40001) as 2b9ee63c2423167cf39d7a5027db944057c74cfd