V8WindowShell::setSecurityToken() - pass around SecurityOrigin.

In some case Frame::m_document isn't available for setSecurityToken(),
This change passes Document pointer to setSecurityToken(), so that
V8WindowShell doesn't need to ask Frame::document().

TEST=viewsource-1.html
BUG=331061
R=abarth,eseidel

Review URL: https://codereview.chromium.org/128033002

git-svn-id: svn://svn.chromium.org/blink/trunk@164748 bbb929c8-8fbe-4397-9dbb-9b2b20218538