Sync the SecurityPolicyViolationEvent interface with the spec

http://w3c.github.io/webappsec/specs/content-security-policy/#securitypolicyviolationevent-interface

BUG=460722

Review URL: https://codereview.chromium.org/1157923004

git-svn-id: svn://svn.chromium.org/blink/trunk@196517 bbb929c8-8fbe-4397-9dbb-9b2b20218538
3 files changed