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/)

Review URL: https://codereview.chromium.org/701133002
Add baselines for the new dashing5 GM

These are all the correct images

TBR=egdaniel@google.com

Review URL: https://codereview.chromium.org/707513002
Remove gm from ignore expectation file

No gm's actually changed from my recent change to dashing gm. This was the desired
outcome since the added calls were lines of length zero

TBR=robertphillips@google.com

BUG=skia:

Review URL: https://codereview.chromium.org/706633002
Add new baselines for remaining dashing5 GM images

This are the baselines for the problem children:
The N5 & N10 gpu images related to Issue 3097
The perspective Windows images

TBR=egdaniel@google.com

Review URL: https://codereview.chromium.org/702143002