[webapi] Integrate 1 test for Animations

 - come from https://github.com/w3c/csswg-test/blob/master/css-animations-1/pseudoElement-002.html

Impacted tests(approved): new 1, update 0, delete 0
Unit test platform: [Android]
Unit test result summary: pass 1, fail 0, block 0
[webapi][XWALK-3088] Update 2 cases for CSP

- Fail Reason: the frame-ancestors is not supported.

Impacted TCs num(approved): New 0, Update 2, Delete 0
Unit test Platform: [Tizen-IVI]
Unit test result summary: Pass 1, Fail 1, Blocked 0
Merge pull request #1560 from yunxiaoxie/delta-cleanup-animations

[webapi] Integrate 1 test for Animations
Merge pull request #1562 from JianfengXu/csp/xwalk-3088

[webapi][XWALK-3088] Update 2 cases for CSP